I got this assembly from C&H sales for $47.50, stock # OL9414.
"Multi-element relay lens assembly. 200 mm focal length.
Front element is 82.75 mm dia. Rear element is 82.75 mm dia.
Excellent for use as a magnifier, or tear down for experiments.
Lenses are mounted in a 103.4 mm dia steel barrel 171.45mm long."
I was thinking of trying this a a relay lens for a large cassegrain
scope. But that never happened. Then I figured the lenses would
make good finder objectives, but I don't have the right tools to
unscrew the reatining rings without risk of damage.
So. I'm offering it on astromart for half price of $23.75 + shipping
from Orlando, FL. If you like it you can get more from C&G :-/