Brian,
Kolle is not bad I owned one of their slot mortiser that I regret selling.
the tenoners are nice but my favorite small manual German tenoner is the Panhans 269 from the late 80s - mid 90s. The table angles both ways to 60 degrees and they had the LAS fence. I think the Kolle only went to 45 each way and the Martin T27 -28 tenoners only 45 degrees one way. Similar to my T23 shaper. It can go the other way but a pain to set and no scale. Some slightly heavier manual tenoners more for window work were the Funk, Okoma and Haberkorn.
All these machines will usually have a 40mm shaft.