So, what is it?
First off, none of it is wood. The case is sheet steel. The bottom is thicker and black. And the top has wood-grained vinyl contact paper on it. Which gives it kind of a '70s low-volume light-industrial vibe.
Second, it isn't for a hobbyist system. One must remember, of course, that those ASCII keyboards that got repurposed, often from surplus, already had a market.
The switch is for selecting whether bit 6 of the output comes from bit 6 or bit 9. The encoder offers both bit shifting and alphabetic shifting and this chooses which. So, it's similar to the switch mod on the TKC encoder board that let it output lowercase if you had the right ROM to handle it. Conversion just means a virtual serial port; all there is is ASCII. But what about the cabling? The longer ribbon cable can't be taken out of the case without cutting it and that's against the rules (that I follow). So, instead, I replaced the daughter card, with two IDC headers, by a straight header between the two cables. A Teensy for the other end.