From the archives of comedy, two rewarding revivals

The veteran Roundabout Theatre Company and the young Mirror Repertory Company have recently dipped into the archives of comic drama. In both instances, the results have been rewarding. The Mirror troupe has completed its 1983-84 agenda with a caring revival of John Patrick's ''The Hasty Heart,'' first presented in 1945.

The Roundabout has reached even further back, giving ''On Approval'' the kind of burnished production that makes Frederick Lonsdale's 1926 British comedy of manners seem mint fresh.

The Hasty Heart

Comedy drama by John Patrick. Directed by Porter Van Zandt.

The Mirror company's mounting of ''The Hasty Heart,'' at the Theatre at St. Peter's Church, achieves a double objective: It proves the durability of John Patrick's group portrait of life in a British Army hospital behind the Assam-Burma front in World War II. At the same time, it confirms the playwright's view that ''The Hasty Heart'' is not primarily a war play.

It is a study in dramatic terms of men whose status as casualties has given them at least a temporary reprieve from combat. More important, it concerns the effects of kindness, affection, and comradeship on a self-isolated outsider.

When Sergeant Lachlen (Victor Slezak) arrives at the hospital's convalescent ward, his five fellow patients have been alerted to a fact of which Lachlen is unaware - namely, that he is a terminal case with a brief time to live. How the assorted fighting men - Yank, Aussie, New Zealander, British cockney, and a silent Basuto - display their concern for the dourly disdainful Scot, and how he responds to their overtures, make for a theater piece in which the resilience of the human spirit responds to, and in a sense surmounts, the tragedy inherent in the situation.

The soldier types assembled by Mr. Patrick (himself an ambulance driver on the Burma front) have been perceptively differentiated under Porter Van Zandt's sensitive direction. They include James Rebhorn's explosively stuttering Southern Yank, Matthew Cowles's good-natured Digger, Tad Jones's Kiwi, Timothy Jenkins's cheerfully overweight Tommy, and Jose Kendall's impressively silent Blossom. Sofia Landon endows Sister (Nurse) Margaret with a charming blend of solicitude and perky humor. F.J. O'Neil's Colonel ''Cobwebs'' is quietly authoritative as the Army surgeon who must finally acquaint Lachlen with the facts of his case.

In the central role of this poignant comedy, Mr. Slezak plays ''Lachy'' with deep conviction, wry humor, and an impressive Scottish burr. He is the acerbic outsider (''a terrible stern man'') whose sharp tongue and arrogant manner challenge the patience and compassion of his good-natured wardmates. From the blunt rebuffs with which he reacts to their initial overtures to the smile that eventually transforms his stony expression (Barrie's John Shand had a similar problem), Mr. Slezak creates the portrait of a man whose self-reliance has been his supreme defense against loneliness and who contrives to scorn the companionship that life has denied him.

Ron Placzek designed the primitive hospital setting where the action occurs, and Mal Sturchio lighted the production. The military wardrobe is by Heidi Hollmann.

Next month the Mirror company will conclude what has been on the whole an impressive first season. With Sabra Jones as artistic director, the company has mounted ''Inheritors,'' ''Paradise Lost,'' ''Rain,'' ''Ghosts,'' and ''The Hasty Heart'' - the two last-mentioned of which remain in repertory. Reflecting their versatility, the company's 47 actors have played 65 roles. At its best, the troupe has made a valuable contribution to the New York theater scene.

On Approval

Comedy by Frederick Lonsdale. Directed by Daniel Gerroll. Starring Mark Capri , John Cunningham, Cynthia Dozier, Jane Summerhays.

Playing light comedy is among the trickiest of histrionic arts, and it is being smartly practiced in ''On Approval,'' at the Roundabout/Susan Bloch Theatre. Frederick Lonsdale's bright and brittle tale begins in London with middle-aged widow Maria's audacious plan for testing a future husband. The exercise winds up in a snowbound Scotland, where Maria's schemes gang more than slightly agley.

The shrewdly frivolous plot involves a four-week ''on approval'' period, during which rich Maria (Jane Summerhays) will test her poor but honorable suitor Richard (John Cunningham), while pickle heiress Helen (Cynthia Dozier) decides whether George, Duke of Bristol (Mark Capri), is really, after all, the peer she would like to be paired with. Everything turns out as Lonsdale - rather than his puppet characters - has planned. Meanwhile, the cast revels in the comic possibilities the script provides.And the audience happily revels along with them.

With ''On Approval,'' actor Daniel Gerroll makes an auspicious American directorial bow. Under his suave guidance, the quartet of attractive players prove their aptitude for Lonsdale's sharp satire, brittle exchanges, and gossamer escapism. They know how to handle the comic bric-a-brac of a piece 60 years old.

As George and Maria, Mr. Capri and Miss Summerhays share the prize for impervious self-absorption. In their own quietly delightful way, Miss Dozier's enchanting Helen and Mr. Cunningham's self-effacing Richard appear to be playing second fiddles until they end up calling the tune.

Set designer Holmes Easley seems equally at home in chic Mayfair or among the servantless rigors of Scotland. The stylish '20s costumes are by Richard Hieronymous. Ronald C. Wallace has lighted the scenes, and Philip Campanella's incidental selections capture the mood of the era in some snazzy, jazzy discs. If this is, as claimed, the first ''major'' staging of ''On Approval'' since its New York premiere in 1926, the Roundabout deserves a gold sovereign for rescuing a pristine comedy from undeserved neglect.