Can you identify this? Pictures included

I got this with an AP refractor a couple of years ago and I need some help with who makes this barlow? When you look at the picture note that the upper barrel has internal diameter of 2" (the end with the two set screws and the opposite end has an outside diameter of 2" as well.

Who is the manufacturer and value?

Many thanks.

Attached Image:

An additional image to help identify. Also no manufacturer marks to identify the maker.

Thank you.

Attached Image:

Its an early AP Barlow Lens. Probably 2x. See
http://www.astromart.com/classifieds/details.asp?classified_id=429162
Value? Maybe $150+ for a collector if its in perfect condition.
With some signs of use, barrel marks, etc. perhaps $100 - $120.

The later version with brass ring and better anodize can be seen at
http://www.astromart.com/classifieds/details.asp?classified_id=346358