Hi Finals
I tried that particular tack a few years ago. I'm afraid nobody will take the risk. For what it's worth, I bought a 206 jetbox conversion for a good rate from a company that were then prepared to give me some freelance work. You can include the Base & Line check (or whatever we call it now) as part of the conversion and after 3 hours you're up and running. Get used to the 206 and then work expenses for a 355. All in, it should take you 6 months.
PS. Take my advice and give the Grand Prix a miss.........