There is a 22G2XX series of gearbox components that match up with the 22G11XX series. The .xls spreadsheet on the BCF doesn't list all of them, but does give a clue to their existence. Input shaft 22G229 is the clue. This is the input shaft part number from that series. Part 22G1117 is the actual input shaft number in the 22G11XX series. Don't see many of these out there, but they do exist. FWIW, here is a list of the usual suspect gears & part numbers that cross. This is from memory here at work, my list is at home, but I'll do my best.
22G229=22G1117 Input gear
22G240=22G1114 Reverse gear
22G232=22G1100 Laygear
22G239=22G1118 1/2/R Slide gear
22G236=22G1121 3rd gear
22G234=22G1120 2nd gear
22G95 Early 3/4 Slide Gear
22G410 Later 3/4 Slide Gear (fully interchangeable with the 22G95)
These apply to the ribcase gear boxes. If you are looking at smoothcase gear boxes, then there are some Morris Minor gear that can interchange, but these are very rare and depending upon which ones they are, may have co-dependencies. That is, to use the input gear, you have to use a certain laygear as well, but 1st, 2nd and 3rd will work with the different laygear.
HTH,
Mike Miller