[folivier]

Good strategy. That's exactly how we found our current Foretravel. We had a relationship with Mel at MOT who knew what we were looking for and called us as the owners were signing the papers to put it on consignment. I put a refundable deposit on it and bought it after inspecting it. Also when we bought our 1998 Newell also at MOT we called about it and put a deposit on it to hold it until we could get there. Interestingly someone else had been looking at the Newell and decided to buy it just after we put a deposit on it. And we've become good friends with them since then.
But you need to be able to trust the dealer and salesman. Hope it goes well for you.
In today's market if you're serious you need to be ready to jump, putting a refundable deposit until you can inspect one is a great strategy.