3 Merriman Block Snap Snatch Shackle Pulleys Nicro / Ronstan ?

Description

I picked these pulleys up at an estate sale. I don.t know much about them. I thought some one would want. They have staining on the rubber and the metal parts have metal corrosion. I don't know how well they will clean up ? I don't know what the markings on the metal snaps mean. It looks like this type of pulley can be expensive.
They seem to be complete. They work but a couple are stiff. I think some oil will loosen them up ? You will have to be the judge.
Thanks for looking and if you have any questions, just message me.