All of the '69S RPMs are relatively minor, but always fun to find them. The die markers on this one are a match for LMDS.
I personally use a 30x hastings triplet, but you should be able to pick it up with lower magnification as long as the optics are good. Probably equally as important to finding these is having the proper, close lighting so that you can pick up the shadows from the seperation lines.
