I have a couple of the firepowerRC 75gal tanks and there pretty nice looking parts, the ones I have also include a mounting loop to attach the tank to the plane, its just a eyelet but you can use the basic mount to adapt a dropping mech. for your plane, there the perfect size for the 60 size Top Flite planes,
I got mine for a Mustang but there the right size for the P-40 as well, the parts come as a kit so you will need to assemble the tank just like the TF offering one thing I noticed is the plastic is thicker in the firepower parts, the TF stuff( I have one of the 108gal tanks as well) is thinner plastic I am not sure how well they would hold up being dropped from a flying plane over time.