One of a series of plays about life in fictional small town Tuna, Texas, “A Tuna Christmas,” has been a holiday regional theater staple for close to 20 years. Maybe it’s time for a new tradition.

Time has not worn well on “Tuna” and its gentle satire of simple country folk. While the concept and the show’s use of just two actors to play more than 20 roles is admirable, most of its small-town humor would be better off staying in the small town.

The Oklahoma City Repertory Theatre production of “A Tuna Christmas” stars Oklahoma City theater veteran Jonathan Beck Reed and CityRep artistic director Donald Jordan in a pair of earnest performances that nonetheless slip into minor variations on the same redneck as the show progresses.

Reed and Jordan spend much of the show in drag, with the varying level of shrillness the only distinguishing factor in most of their female characters. If not for Jane Childs’s wacky costume design, there would hardly be a difference at all.

“A Tuna Christmas” takes place during Tuna’s annual Christmas yard display contest, where big fish in a small pond Vera Carp (Reed) is looking for her 15th straight victory. There’s a yard display vandal on the loose though, dubbed “the Phantom” by the wary townsfolk.

Other peculiar Tuna residents include harried housewife Bertha Bumiller, former wartime riveter Pearl Burris, the town sheriff nicknamed Rubber Sheets and “not-the-marrying-kind” theater director Joe Bob Lipsey (all Jordan), as well as Bertha’s kids — hyper Jody, ex-con Stanley and petulant Charlene — and crazed weapons saleswoman Didi Snavely (all Reed). Radio station OKKK disc jockeys Thurston Wheelis and Arles Struvie guide the story along.

There are some potent barbs to be found among the diluted sarcasm (“Censorship is as American as apple pie, so shut up!”) but much of the humor will only tickle the funny bone of those who bust a gut at jokes pointing out differences between Methodists and Baptists. The absurdities of small-town residents may be an easy comedic target, but simply making observations about them doesn’t exactly equal comedy.

Reed and Jordan work harder than most theater productions require, with a flurry of costume changes and a lot of running around involved. Their weariness as the show progresses is understandable, but the comic timing suffers as the show goes on.

Scenic and lighting design by Don Childs effectively create the look of a rural kitchen, a radio station, a diner and a weapons supply shop.

“A Tuna Christmas” isn’t exactly a lump of coal in your stocking; more like that sweater that would’ve been fashionable a decade ago from your out-of-touch aunt.

The play stages now through Dec. 13 in the CitySpace Theatre at the Civic Center Music Hall in Oklahoma City.