I think I'd keep the old tank for historical purposes, install a flat
plastic tank for real use. I did run across a place that makes custom
aluminum fuel tanks, your choice of size, fill, and drain locations.
Price was not cheap but not horrible either.

BFR wrote:
Bruce, those are good suggestions. The tank doesn't actually bolt
together, it's welded. When I say it's a clamshell type I meant that
it was made of an upper and lower half, pretty much identical, with
mating flanges that were welded where the edges join. I separated them
by simply grinding off enough of the outside edge of the flanges to get
rid of the weld and, voila, the two halves came apart. After cleaning
the insides, I welded them back together the same way they were before.
I could follow that same procedure over and over again until there was
no more flange, I suppose, but the flanges mated for close to 3/4's of
an inch so there's plenty of meat there. I think I may just follow
your suggestion to mothball the tank (I can't hot dip it for two
reasons, (1) It's pretty thin sheet metal and I'm afraid it would warp,
and (2) Welding it back together after it was hotdipped is problematic
at best.)

I have gone to great pains to preserve the originality of the machine
because I bought it from the original purchaser who bought it new in
1937, kept it in indoors and in great shape until 1995 when he retired
and sold it to me. Everything was there - original paint, decals, etc.
and most importantly, the side panels - he even pulled the original
manual and sales brochure out of the file cabinet in his office.
Imagine that he actually had three very similar machines for sale when
he retired, I just bought what I thought was the best one, but they
were quite similar.

Your suggestion to hot dip the tank was interesting - I've always
wondered whether the zinc would be fuel impervious or would flake off
eventually.

Thanks.

Bruce