Printed it, but needs some modding to make the lock better.
Thingiverse started to work, but need to wait 24h to post...
I'm probably the wrong person to try to measure these accurately. I have calipers, but no expertise with trying to figure out how to measure the distances when surfaces are offset, curved, etc. But since the purchase of my YS-01 and YS-02 hasn't happened yet, I still have them here.
My best estimates:
Distance from front of strobe to beginning of diffuser grooves - 19.5(ish)mm
Width of diffuser groove - 1.8mm
Length of diffuser groove (following the surface of the strobe body) - 24.0mm
The toughest one is distance from top. Very roughly, from the top of the strobe (edge of the clear plastic front), adjoining the black body to the top of the diffuser groove is ~17.5mm - but that's just eyeballing a straight edge tangent to the top, then measuring a perpendicular from that straight edge to the top of the groove. But if you don't try to fill the entire groove, but allow some space at top and bottom for likely mismeasurement, you should be able to get things that go into the grooves.
Oh - but I just realized you said "the two holes made for the diffuser." My S&S diffusers click into grooves below the round holes just realized I think you are referring to and don't relate to the holes at all. But the holes would give a better grip. I am measuring on the upper holes. The diameter of those holes is 4.8mm. Position, as above, is trickier/less precise. I get ~23.85mm from the back side of the hole to the front of the strobe; with the hole 4.8mm diameter, that would mean 23.05mm (so maybe really 23mm) from the front face of the strobe. The bottom edge of the hole is even with the top of the diffuser groove, so based on my above measurements, that would put the top of the hole ~(17.5-4.8)mm, or ~12.7mm down a perpendicular from a tangent to the top of the strobe.
Do those measurements help? Or can you suggest a more accurate way to measure? Happy to try to help, though I think you'll likely have to print and expect to adjust things a bit no matter what.
Oh, if you are interested in trying to use the grooves, the diffuser has little grips 20mm long x 1.5mm wide x 1.6mm deep.
And anybody out there with YS-110a snoot files, love to hear from you!