Ok so to clear things up the shifter I made seams to have too much weight. So with it being built as a better lever, than the more up and down design from stock. It feels like any significant bump could cause the transfercase to shift, due to the internal detents being fairly insignificant. First 3 pics show how big a difference there is.
The benefits to my design are that the shifter ends up in the correct location next to the transmission shifter instead of being several inches behind which would have put it under the bench seat, shown in 3rd pic. I'm not sure how you guys have gotten around that putting an m50d in a 1st gen, with a stock transfercase shifter.
So I started thinking about making my own auxiliary shift lock. My first thoughts were a ratcheting system, however space constraints, and total shift throw didn't leave me with many good ideas. Than I moved on to the next idea of a spring loaded lock pin actuated by a bicycle brake cable, however again the limited shift throw didn't leave enough space for all 4 detents in a single arc. 2hi 4 hi and neutral are super close. So was born a terrible 12 am drawing of a half thought out dual spring loaded lock pin system, that is shown in the first post. Than today I built it.
The first of the above pics is the spring loaded pins, the second showes where on the shifter they will sit, there will be a plate mounted to the transmision with detent holes, the top pin will be 2hi, and neutral, the second pin will be 4hi and 4 low. This configuration allows proper spacing for each detent hole for a very secure shift lock. Only one spring loaded pin will actually be actively engaged in any given gear. Long term this could cause wear issues due to pins dragging against the plate, however with how infrequently the shifter is moved it would be a long time out. This last pic shows with the green wire approximately how the bike brake cable will run from the shifter to the actuator for the pins. Once I'm happy with the full assembly, I will install a zert fitting, and fully box in all the moving parts and fill with grease that way it will be protected from debris, and rust.