Welcome to the forums. First off, I am sorry you own a Harley. LOL. I had too...
There are not many collectors of classic MV's, and the ones that do, are very savvy to the prices. But, like most classic motorcycles, they are again a niche market and prices are usually lower then you would expect. Restoring one will usually end up in you spending more than the bike is worth to the next man.
What you are talking about, I have seen for in the $3000-$3500 area, restored. I have been hunting for a specific one myself, so I somewhat know the market in that CC range. It sounds like you are more interested in turning a profit from your purchase.
If you are genuinely interested in keeping it and being an MV owner, fantastic, great find. You would be hard pressed to make any money on reselling an older MV. They are like classic dirt bikes, only the original owner would love them..
May you live as long as you want, but not want as long as you live