You can buy the whole dialgauge and adapter online from outside Pakistan, in other countries mechanics who work on old diesels actually own this piece of instrumentation.
Problem in Pakistan is that a lot of idiots are mechanics and dont own anything else than a few hand tools. Then they believe in the “hamara andaaza” type fixes.
So to remedy this, you can either look for it as a toyota genuine special service tool (Indus motors actually supplied these to all dealerships when they sold and serviced the 2.0D models)
A lot of those tools ended up sold privately, some seasoned machinists infact know exactly what it is and can make it for you out of brass stock. You can give a pump center plug to a machinist to make an adapter for you, the whole thing needs a hole in the middle for a pin needle (also brass) and the end of the adapter should be able to hold a dialgauge in place
