>>Now, after a while, to test your mettle with wheelbuilding..use an old hub, used, light, tubular rim(like Fiamme Yellow-DOH), thin spokes and not enough of them..
Old pal, I think I may already have one in the garage...is the set of old tubular wheels that came with the old steel Bianchi that I bought to do a 650b conversion two years ago. It's been sitting there in the corner. After you mentioned it, I picked the front wheel up between the spokes to examine and just doing that I broke a spoke, very brittle. The tubs on it are already flaking and breaking apart, even the QR is old-school skewer, I can only imagine how old it is...but other than the spokes. the rim seems in fairly good condition.
The label says, Sun Mistral...and it has a warning sticker that says. For Race Use Only.