There is hardly any weight penalty for using the the thicker 0.040 material and even though it's only eight thousandths of an inch thicker, it is much easier to handle without dinging or creasing, so I'll probably use it if the price isn't prohibitive.
The worst part is that I'm just about ready to begin skinning my teardrop-- I could start early next week if I had the materials. Now I have to put the build on hold for at least a couple of weeks! I suppose the alternative is renting a truck (my pickup won't handle sheets that size) and driving to San Francisco, Sacramento, or Portland (where the metals dealer will buy the aluminum)-- all six or more hours distant.

If anyone in the Eureka CA area knows of anyone who has either a five foot roll of aluminum or 5 x 10 sheets, or any other similarly durable skin material, I'd really appreciate hearing about it. I've talked with Century Service (trailer repair), Wright's RV, the RV place out on the 101 at Indianola, and a couple of sign shops (Eureka Neon?). Nada. The metals dealer that will order for me is Eureka Boiler in Arcata.
--Mike C.