Regarding W30 converts, or even W30 cars in general, I would be very careful of any cars without bulletproof docs and a verifiable owner history. I've been tracking these cars for years since I bought my first W30 convert in 1988 (still own it) from the original owner. Back then, chances were if the car had the right "bits" it was real because some of the W30 stuff was either very hard to obtain, or the details that "made" a W30 were obscure enough that most people didn't know how to fake them or it just wasn't worth the trouble as even W30's weren't that expensive. Most guys plopped on W30 emblems and red fender liners along with a 'glass hood and left it at that. Saw a lot of "W30" cars with cast iron intakes and non-RA air cleaners back in the day!
However, in the last decade the availibility of W30 repop parts and the INFORMATION being made available on how these cars were built in various books, magazines, and the internet has made it very easy to build a very convincing fake W car. Today you can call a well-known vendor and order the heads, intake, a stamped carb, an OW trans tag, fender liners, emblems, hood, etc and build a dead-nuts W30 car. You can even get a "real" build sheet by making a few calls.
Unlike a lot of other cars with vins encoded with engine data, W30 cars other than the Lansing plant code are just the same as other 442's.
For 10 years I looked for another W30 'vert and passed on a ton of them until I found my latest one about 3 years ago. Has all the docs from the window sticker to 3 build sheets, original dealer paperwork, etc. Had the original top, paint, interior, etc and the engine had never been out. It was a joy to restore as every nut and bolt was there and real. If you get a good W30 it is well worth the hunt as they are fantastic and extremely rare cars imho.
This in no way is a commentary on Dave's cars or any other cars at the Mecum auction. Just my thoughts on buying a W30 in general. Paperwork and history is paramount in this day and age with "new" W30 cars being minted daily! Buy a known car with docs and you'll be able to sleep at night
Colin