Question about 1961 era shoulder boards

[Tonomachi]

I don't know very much about shoulder boards and recently picked up an Army Chemical Officer Dress uniform at the flea market that is dated 1961 on the inner pocket label. The shoulder boards are missing and noticed that they are secured with four metal press studs. It seems that all of the replacement shoulder boards that I have come across are secured with two metal hook clips instead of 4 press stud buttons. So are the four press stud shoulder boards and older way of attaching shoulder boards and will be harder to locate?