Here's a TRW sprocket, with holes.
https://www.ebay.com/itm/TRW-S-305-T...8AAOSw42Fbc4Rb
So, for those who want this type sprocket and a Morse chain, they are still available, even if you have to order the pieces individually, in an NOS condition.
Again, here's a set that SHOWS the S.A. Gear sprockets, with a chain that appears to have the word MORSE, on a couple of links.
https://www.ebay.com/itm/ENGINE-PRO-....c100005.m1851