Is it possible to buy the whole truck assembly AND side frames from the Vision model? I mean, they're both scale models of the GG-1, right? Assuming the shells are the same, if you wanted to spend a fortune and buy side frames, truck blocks, motors, chassis, etc., and swap parts, you would eventually end up with an operable model.
Caveat Emptor, I know. But zinc pest (and the lack of replacement parts) is a big issue. There ought to be a persistent "watch list" on the Forum, or somewhere else on the web that folks can refer to, and be informed that there's a known risk of zinc rot for certain products.
It's true that if a pricey loco lands on the watch list, this could devalue a dealer's shelf inventory, especially if he or she has multiple examples in stock. However, that dealer has more leverage to go back to the manufacturer and force a run of replacement parts than individual buyers do. A dealer also has the option to take a markdown on the value of inventory ("write-off") and sell them as-is with full disclosure.
For example: I've always been curious about the 763E / 700E. Cost aside, I've seen & heard enough about warped frames, crumbling tenders, etc. I don't have $2500 to lose, so I just stay away!! The early 700E is a well-known case. All I'm saying is, there's enough combined knowledge on the Forum to create a modern era list. It could even drive an effort by the OE manufacturers (or cottage 3D printers, etc.), to re-run critical and hard-to-find parts.
This is part of how the TCA was born. By the 1950s, many of the standard gauge classics suffered from crumbling wheels, pilots, trim parts, etc. Great folks like MEW, Hennings, etc., became aware of the need and reissued them, from the original or new tooling. Now I know there's a LOT more variety in production today than there was with the mass-produced trains of the '20s & 30s. But we also have a vastly improved ability to share information, and when 3D printing matures, perhaps a better means of making the parts in small batches.
Let's think about it!