I think I've figured out the segments. Mupet Wiki's page for epsidoe 83 includes a segment where Bob and Mr. Hooper build an A, and the first season shwo content mentions a "Crossover A" with Bob and Mr. Hooper being in that epsiode. And the page for epsidoe 162 mentions a similar skit with Bob and Gordon putting an H together, and the files mention a "Crossover H" segment with Bob and Gordon (obviously, the "firs tseason shwo content" doens't list any second season epsidoes that it appears in, but we can put two and two together). Oddly enough, there was another H segment liek this, in one of the Old School Volume 2 epsidoes. I wodner if that counts as part of the "crossover" series, and if it does, it's weird that another H sketchw as done (unless it was considered a remake, done so that it could be in future epsiodes without having to include Matt Robinson).