Help please on a "NOS" Seamaster 300M

Help please. I have a put-together "Watchco"-style Seamaster 300M that came with the 1171 bracelet and correct end links. The problem is the endlinks I have rattle hopelessly. I am quite handy at fettling rattly endlinks, but these can't be bent to fit tightly because they don't reach the sides of the case. I realised that perhaps the service/NOS case is slightly different from the original case and maybe doesn't work with the original endlinks.

I have solved the problem for the time being by fitting my new Speedmaster 1998 bracelet, which fits perfectly. I also have an Omega mesh bracelet. But I would really like to give the 1171 bracelet a try without all the jangling.

Can anyone recommend an endlink that works with the 1171 bracelet and works with the service case I have on my Watchco? Is it 677s I want?

I am wearing mine on mesh right now but I think most use 633's with their Watchcos. 1171's are notoriously rattely even with snug end links. I hope you find a solution.