mystery mtb frame, steel lightweight interesting seat lug

[vintagebicycleman]

http://img1.jpegbay.com/gallery/004630130/1_m.jpg
http://img1.jpegbay.com/gallery/004630130/2_m.jpg
http://img1.jpegbay.com/gallery/004630130/3_m.jpg
http://img1.jpegbay.com/gallery/004630130/4_m.jpg
http://img1.jpegbay.com/gallery/004630130/5_m.jpg
http://img1.jpegbay.com/gallery/004630130/6_m.jpg

Any ideas what this frame could be it has 2C 51 stamped in to the BB and an interesting seat cluster.

 

[Shayne]

Re:

NM

 

[integerspin]

Any ideas what this frame could be it has 2C 51 stamped in to the BB and an interesting seat cluster.