But are the clothes the British sailors worn in this sketch accurate for that era? I ask because I thought the Monty Python people were actually persnickety about such details.

Well, Python, might have been persnickety about the details, but I think the BBC prop closet is kinda thin. IIRC there's an orange space suit that the Doctor has worn in at least 2 series that was also used in one of the Star Wars films.

When it comes to historical costumes no one has the range or array that the BBC does. It's vast. And the detailing is extraordinary. And sometimes what is in there is surprising, like the Panzershreck rocket launcher that showed up in the British Dental Association sketch.

Any number of BBC-TV produced series have extra bits on costuming in the DVD sets.

Which sketch? Is there a missing link?

Lifeboat Sketch

https://www.youtube.com/watch?v=8sljSf7KVlQ

Oh yeah...discussing who to eat first! That's even funnier than Trumpolitics!

Tropical rig for the enlisted and officers. Michael Palin might be a engineer so wearing a unofficial shirt. John Cleese who is called the captain is really only a lieutenant which was typically not the commander of any vessel outside of a submarine?

In the killer joke skit the uniforms are very accurate for Wotld War 2 British. And in the big game hunter (mosquitoes) skit ends with them standing on a Conqueror tank.

The link I forgot:
https://www.youtube.com/watch?v=3DlN4Sh06po&t=212s