In the end the only way is to buy an electric Vacuum Pump and try it.
I could at least use it on my Stick Shift Volvo as it only needs Vacuum for the Brake Booster.
And, while a Vacuum Pump failure on the Volvo will not injure the engine you won't find a used one at the junk yard and a new one is as much as a Mercedes Vacuum pump.
Also I replaced the Volvo Alternator long ago with a Delco one and it should handle the extra AMPs of an electric Vacuum Pump.

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84 300D, 82 Volvo 244Gl Diesel