Re: DIY tank... even if you can't weld
I bought a pack of those, too, several years ago and never did do anything with them... had to have them, though. Your weld looks good to me. Go for it! I hope it works out. That would probably clean up nicely with a flap disc, polish it and put your name on it.
Someday when I grow up I will probably lose interest in toys with wheels, but until then...