Having bought
the tailpiece, I started looking around for a tank. Valentini stuff
isn't common, but ebay came through again and I bought a tank and
another tailpiece from a vendor in Belgium.

The second
tailpiece turned out to have a longer seat than the first. It wasn't
a modification, but had been moulded that way.

The tank and
seats are both the earlier style, which is the one I prefer, but
there seem to have been several versions of Valentini bodywork.