Sherpamustache
Retro Guru
that is . The '89 Signature JT frame is not the same as the one in the ad. Nothing to do with each otherThat’s a 1990 Mongoose IBOC Signature, marketed after Tomac went to Yeti for a year.
Front triangle and 1/3 of chainstays are made by Merlin and are Ti.
Rear monostay, dropouts and 2/3 chainstays are steel, the tubing being Prestige.
The 1989 all Merlin Ti monostay frame is the Mongoose John Tomac Signature model.