Where are you writing from Johnson?
Such projects really get me all excited too. The thought of bringing back to live some classic model. But I would think this 75 classic would need minimal upkeep once the engine is rebuilt as it runs on plain mechanice with every little electronic wiring. For such an age, I would think that most of the wires and moving parts needing some form of lubing to get it out from having been well dried, and getting the idle to run smooth.
The only concern would be the consumption as the 75 450 is known to drink by the gallons. It has some power, but at a cost.
Rust is again another factor to consider. For this age, depending of how well it has been kept under wraps, rust is one thing that will make the difference between a classic vintage, and a classic scrap.
If this was in Malaysia, it would not be more than US$1,000 - again depending on the condition.
Do tell us more.
126 tailed by a 203, 129 leading the pack.