Correction to what I posted in Post #9: I did not order the MPF rails, I ordered the other ones from Bullpuparmory.com
I had them for a few days now and I finally just installed them.
It's a very well machined piece and I really like the QD slot.
When you buy these, you only get
one rail.
You have must orxer two of them if you need a rail on both sides of your PS90
For now, I have the QD slot forward, and I installed a tac light with the head of the light over the QD slot, so detaching the sling is not an option for me.
I am considering turning the rail around with the QD slot to the rear of my light.