Dr. Tommy: The only mount I know that has 6 screws and looks like that is the BKL 260. I have a couple of them myself - hek of a mount if you have Magnum springers. Indestructible. I also use a BKL 260 on my mid-powered Diana 36 too.
If I had to guess I 'd say this one is probably the 260D4 or D7 that offers 0.004" or 0.007" droop compensation. BKL makes a regular 260 with no droop compensation and also 260 with high rings, but again with no drop comp. The D4 & D7 only come with standard (medium) height rings.
I said indestructible because when my 1st BKL 260-D7 arrived from SS, the dog (about a year old - untrained & undesciplined) from across the street snatched the small UPS box while we were out. He had done that with other UPS/Fedex packages and to other neighbors in the past.. He chewed it really bad so by the time I started wondering a couple of days later where the package is, he had taken it out of the plastic and was playing with it for more than 48hrs. We found the UPS packing slip (chewed up) and remains of the cardboard box on the neighbor's lawn but the mount itself was nowhere to be found, just the pieces of the hard plastic container everywhere. I finally found it like 3-4 days later in the middle of the street about 130yds up the road. It had gotten run over by cars and it had small tiny indentations and scratches from the dog's canines and was full of mud. After I cleaned it, I used it and it's fully functional! I would have thought this dog's teeth would have done more damage, but the tiny hair scratches are microscopic as are the little surface puncture marks - like the size of a pin needle, very had to see. The neighbor said she remembers the dog chewing on it for hours and she was wondering what it had in its mouth! The got rid of the dog a few months ago while it was still a puppy at just over 1yr old. They never walked it or tried to train it, so they shouldn't have a dog at all.
