I have a full set of Generations dating back to the late 1960s. The are the red topped brass ones, which were cheaper than the blue topped chrome (?) ones.

They are (lowest to highest) Bb, C, D, Eb, F, and G, and I also have a D tabor pipe, and a tunable low G tabor pipe.

Maybe it's because they are so old, but I've never had issues with their playability or intonation - though the high G can be a bit tricky to blow without squeaking.

I also have a couple of 'C' Clarkes and a plastic 'D' Susato...