@xeno: No this just raises the age at which players might retire. And even this could do with some more testing! Not come across the issue where players do not retire at all - so hard for me to fix.
EDIT: Ahhh, this patch needs looking into - I think it could possibly cause what you're stating (i.e. players never retiring). Will look into it and come up with another patch.
EDIT2: Erased
EDIT3:
This has been waaaay trickier than I thought it would be - this is a little bit of a hack, but does work and forces the earliest retirement age that can occur to be 34 (that's the 0x22 at offset 003A65C9 if you want to change to a different number). But at least this patch for it works! 
Code:
003A6585: 88 EB
003A6586: 08 3F
003A65C6: 90 80
003A65C7: 90 7F
003A65C8: 90 FE
003A65C9: 90 22
003A65CA: 90 7C
003A65CB: 90 BB
003A65CC: 90 88
003A65CD: 90 08
003A65CE: 90 EB
003A65CF: 90 B7