Re: gluing fabric to surface of the tanks... I'll throw this out - If your tanks have a perfectly smooth surface and are made & mounted such that the surface height matches that of the wing ribs, then gluing the fabric to it should be fine (probably done as Jerrytex described). If not smooth, and especially if the surfaces don't match the upper & lower elevations of the ribs, adding false ribs to the tank surfaces would seem to be the way to go, gluing the fabric to the false ribs & shrinking it the same as you do between ordinary ribs. That's what I had to do on my 7SS. Many of us mount the false ribs on small standoffs, matching the contour of the ribs & allowing the fabric to be laced to them with the proper technique, although I don't think that's absolutely necessary. I know of Mod. IV builders who laid down a layer of felt-like material over the tanks to insure that the fabric didn't stick to it or rub on it, and to insure a smooth surface. I also know that some (most?) do not even attempt to lace the fabric to those false ribs, and some even glue on "fake lacing" to maintain a uniform look.