Unlikely
The DSOTM lug width is 21mm
The PO will be 22mm , rubber does tend to be more forgiving... But these are integrated straps... And may not hug the case of the Speedmaster the way it does the PO
Aw, that's a pity. I've learned to love the DSOTM strap and it would be great to have something identical but in quality rubber for use in really hot months.