Argh integrated straps! I think someone used to do a 'converter' attachment for solving this issue with these sort of straps, similar to those that enabled Casio G-shocks to be fitted with std. NATO straps... The Casio ones had something like a 16mm block one end but with std. 20mm gap 'lugs' at the other end... Haven't seen them recently though!
An adapter would be an excellent idea - google is giving me no joy though - do you recall where you saw them before?