So we know that Fred Thursday was based in North Africa and in Italy during the Second World War. We know that he was promoted to sergeant at some point during it, and that a lot of what he did was hush-hush. We know that he worked with some Italian rebels against the Nazis.

So I see absolutely no reason why he and his company didn’t sometimes join forces with the Howling Commandos. It would seem pretty likely in fact.

Also we know that by the start of Endeavour he is noticeably anti-homophobic. And call that partly having grown up in the East End and partly just general having been in the army at that time, and being extremely anti-fascist for all the obvious reasons. But I imagine it would also help if, e.g., he’d got to know Capt. Steve Rogers and Sgt. Bucky Barnes actually quite well (especially the latter? all protective NCOs together ;-) ) and had observed precisely what was going on there. :D The “deaths” of each of Steve and Bucky would have hit him hard.

And now if Steve’s found a lot earlier than in the MCU - early 70s, say? - and through the means of Oxford academics so he ends up in England, and if the Winter Soldier is thus sent after him a lot earlier...

Anyway. I don’t have the time or spoons to start on that crossover any time soon, but in case anyone would like it. ;-)