The headstock is stamped with a serial number (701231) and "DM450M3", and to the best of my knowledge the frame is completely straight and is unmolested, that is to say it has all the brackets for tool boxes, wiring hooks, a solid battery tray and the like.
Note that the 450 frame has integral frame stiffeners that run along the main tube leading rearward from the headstock. These were intended to add rigidity to the frame, either for the added weight of the engine or the extra power or both. Here again it differs from the Mototrans frame in that the stiffeners bend and travel down along the front edges of the rear sub-frame. The Mototrans frames don't have the stiffeners tied to the subframe (to the best of my knowledge).
The stiffeners do limit your choice of fuels tanks as the tanks made for the 450 had a wider ‘span’ so as to straddle the stiffeners.
I don’t know of any reason why this 450 wide case frame couldn’t also hold a 250 or 350 widecase
engine.
The frame is currently in northern Illinois. I can ship it but it is heavy and shipping charges would be at your expense.
The asking price is $500 given it’s rarity. Please private message me for hi-res photos or with questions.
Jim