Writing this in Jan 2025, having seen series 3 of this show on That's TV channel. And I'm now sure I never saw the originals, though I was definitely one of the huge audience who'd seen series 1 and 2, when Penny & Vince's stop-start romance drew viewers in droves, numbers that would have been the envy of many modern sitcoms!
I cannot recall why I missed this final series, not even sure where I was that year (1986 -- the last episode of all went out on Xmas Day, it seems).
As a couple of reviewers have hinted, the last series wasn't quite as funny as the first 2, it had a few tricky storylines to explain and tie-up, but even that level of humour puts it well ahead of lots of feeble 'comedies' we've had inflicted on us since the Millennium!
And it was a shame that they chose an actress to play Vince's wife -- estranged and divorcing whilst taking him for every possible part of his business -- that seemed to be doing acting by numbers, an unusual weak link in this cast?
BUT -- it was all sorted out well in the end, and Vince & Penny did eventually 'tie the knot', albeit in a Paris Town Hall/register office, with a couple of cleaners for witnesses, no friends or family.
Some viewers catching up years later may apparently not always see the final joke of each episode (depends how you're accessing it), which unusually was AFTER the 'closing' titles, one closing scene, quite often with Vince cracking yet another gag. In THIS episode, it's mentioned in the 'quotes' just above 'user reviews', and it's a cracker!
I think it's a shame that BBC never commissioned a further series, could have explored what happened to the 2 leads a few years later, but feasibly the writer John Sullivan (also did the amazing, much acclaimed 'Only Fools' of course) had just run out of ideas for them, and/or wanted to explore further creations? He was pretty busy with other projects, in later years, though (IMO) he'd have served viewers better with a JGF follow-up instead of the mostly laughter-free 'Heartburn Hotel', and the utterly abysmal Green Green Grass (a spin-off from OFAH that was only needing a soundtrack of someone loudly scraping a barrel?!).
So, we never found out what happened to them in Paris, (could Vince get a job?) or when they doubtless came back to England, and on the way produced a child or two, lots of avenues to explore.
But I'm glad I caught up with the show again, hadn't thought of it for 4 decades, and I see the 2 leads are still with us, I hope time (& life) has been kind to them.