In my other post here:
https://www.d24t.com/showthread.php?t=2036
I've come across a potential solution to the waxstat shortage.
If the internal part of an appropriate thermostat is removed it should replace a waxstat.
Clockwise from upper left: the valve from the oil distributor on my 2.0TD, the thermostat (or waxstat) from that valve, the internal part from a 1.6 TD thermostat, a complete 1.6TD thermostat.
I'll post any solutions in my search for a correct thermostat/waxstat on that thread.