I had a Gianelli once but i used my bike a lot back then and didnt regularly paint it, so like all the others it ended up rotten, you just dont see them any longer, even on ebay, last one i saw on ebay had been powder coated...as the Americans might say...go figure!
You say your Gianelli has a pipe in a pipe, but my stock one has a big air gap between the two like this