Seems like it's been written by a random line generator. Example below.
Reginald: Why hello Henry you homosexual that I admire for being true to yourself in a totally not 1970's stereotyped way.
Somewhere buried deep within that line buried deep in the middle of some other exchanges it seems like there's a point being made about 1970s asexual camp characters vs blokes that actually have sexual relations with other blokes. There's an obvious counterpoint to be made about lecherous double-entendre spouting old men like Reg being far more acceptable in the Seventies than they are now. Unfortunately the line itself isn't intrinsically funny, in lieu of a punchline we have "Hello Reg", and nothing else in the script even slightly alludes to Henry's sexuality.
Whoever ends up writing/rewriting needs to (i) think more about making something that flows something like an actual conversation and (ii) make sure that the observations they're looking to make about Seventies sitcom are actually made. That would make a more compelling script even without adding actual jokes.