Made the cord with an IBM M SDL to PS/2 cable (replaced the SDL connector with a RJ11 (6 pin) connector). The colour of the IBM cable wires did not match with the wires of the WANG. After scrutinising the SDL connector, I arrived at the conclusion that:
Looking from the bottom of the KBD connector with Sandy55 info to match the IBM Cable wire colour.
1} KBD White wire = Clock = IBM cable Brown wire
2} KBD Black wire = Data = IBM Cable White wire
3} KBD Red wire = N/C = Blank
4} KBD Green wire = Ground =IBM Cable Black wire
5} KBD Yellow wire = +5V = IBM Cable Red wire
6} KBD Blue wire = Shield = Metal Wire (bare)
Please note that this applies to the IBM M SDL to PS/2 cable, other cables may have different colour coded wiring, so you will need to check which represents "Data", "+5V", "Ground" etc etc etc.
Skeptical when I connected to my PC, then powered on. To my elation, it worked perfectly with a extra pleasant surprise. I had forgotten there was a small speaker on this KBD, and every key stroke produced a bleep sound which can be turned louder or quieter from the back of KBD. So modding this ALPS Black switches KBD to become clicky is unnecessary and this bleep/noise is uniform which may/may not apply to clicky switches.
To summarise this WANG 724 = "Delightful"