I recently received a Detonics .45 with no MK ~ings it is mate black absolutely beautiful, flat top slide fixed sights 6 rnd mag. Spured hammer is very spured. The serial number is also marked inside the slide under neath. It is stamped Detonics Assocs. Seattle Wa. I am a looking for the date of manufacture or what I actually have. The serial #I 6578. Fit finish and workmanship is a work of art. Its not an essex frame that I am familiar with. The slide is flat top like the colt gold cup. Recoil spring is containted 2 springs with wood grips. I was given the piece by a relative to carry as a off duty/backup. I have had a stainless mkv1 years ago I would rate this one at 98% it is a piece of art. I can send pics if need be. Any info help is appriciated. My brothers and sisters we need to stand together and protect our liberty before the liberal/progressives steal it. God Bless America for We The People /Dennis B.