Good morning,
I hope all is well with everyone. I have. A question…. I have a set of older meprolight sites on a 19. Before I install a Holosun SCS on a MOS 19 I just picked up, I was thinking of putting the old 3 dot sights on there. They are dim but I was thinking they are at least better than the factory…. I am new to the RDS thing and hear you have no need for irons, but I am not there yet. Will the older Gen meprolights fit on the MOS?

Yes, standard Glock iron sights fit the MOS models.

(With most red dots you'd need taller "suppressor height" Glock sights due to the added height of the optic, but the Holosun SCS is specifically designed to be low enough to be usable with normal height Glock sights.)

The SCS will co-witness just fine with stock Glock/stock Glock height sights. I have so far had a very good experience with the SCS but I have to get it out more.

Take care, shoot safe.
Chris

Ive had my holosun emitter malfunction on me- back up signts are 100% needed. Make sure whatever you put on there works with the field of view of the optic.

The dovetail is the same dimensionally, but it is set farther back on the slide. Some sights will hang off the slide if they were originally designed to line up flush with the rear of a "normal" slide. Hopefully that makes sense.