More eccentric British cranks. Williams AB-77 debuted in '62, or maybe a bit later for actual availability.
The "spider" (chainring adapter) big circle is 151 mm BCD so you could use Campy rings of the day. (144 mm rings only came out much later) The small circle is 50.4 BCD so you can use this adapter on TA cranks or any of the many other cranks with that 5-pin pattern. Or put TA rings on the Williams crank.
I heard from some English racers who used these BITD and they had a reputation for the spines on the soft alloy wallowing out and stripping. Didn't happen to me, but I only put maybe 1000 or 2000 miles on them, none of it racing. I do have one arm with stripped splines someone gave me, but I suspect it was ridden loose by someone who was not an adept mechanic.
Mark B