Just completed my collection of SandY watches from model 184 thru 660.
I think it complies with MIL-W-87967, Lysander will know for sure. I thought these watches were plastic but the body is actually anodized aluminum. Type III refers to pilot/navigator or "shallow diver"! Class A refers to a permanent back-light. Still plenty of contrast in the LCD but the tritium back-light is almost dead after about 30 years. Not what you'd call a "sterile" face, eh? Almost as bad as Casio! (ducks).
The axial brush finish on the back makes it hard to photograph the back markings, this is the best out of 1/2 dozen tries:
Curiously, the NSN is the same as that for a Benrus type I per MIL-W-50717. Odd, that. The last number is a U.S. Navy Contract reference, presumably awarded to Stocker&Yale in 1981.
I had SandY leather strap which looks good on this watch IMHO, although the spec calls for a MIL-S-46383 strap.
Need to sell some more quartz, or go broke buying bloody batteries ;-)