Case clamps for a 166.063 case with a 1012 movement

Hi Guys, thanks for all your info and knowledge about my previous post Omega crystals.

However my new conundrum is case clamps and Omega parts numbers, here goes

I have a Omega Geneve case number 166.063 with a movement 1012.

I was trying to source new case clamps as l found out the watch l bought had the case clamps screws but no actual case clamps.

Doing my research l found the parts number for the case clamps 470-1974B for my watch, on seeing an advert for these case clamps, l noticed that there was 470-1974A and 470-1974B
Being naive my simple brain said Oh A and B must be for the opposite ends of the case. So l bought A and B.

However since buying A l was told that B would be the wrong size and that l should've bought 2 B's for this case.

Should l take up the offer from the seller to purchase a second B ?

And if so would anyone be Interested in the A

Thanks Rendo, l have bought a second B case clamp Thanks for your reply