I have been looking for a suitable frame and fork to use up some "take off parts" I've accumulated over the past year and recently found this frame. It has Shimano "Aero" decals and the dropouts have Shimano stampings. I know that Shimano never made frames so I think this might be Tange steel? It is chromed with some pretty fancy lug work and braze ons. There is no serial number. The seller claims it was a limited production used to promote the 600 groupset. Can anybody confirm this? Is there any value in this? because I'm considering removing the decals and building it up "unbranded"