Dutton Kit Cars and their owners
Most 'old school' thermostats are of a very similar design but the specific one listed for a mk2 escort 1300 is
Gates part number TH12888G1
First Line part number FTK003 (kit with gaskets)
Both should be well under £10. Standard opening temperature is 88° but in a Dutton i'd go for 82°.
Housings are a little more awkward to find as they corrode inside the sealing edge. There may be a chance that a later Fiesta one would fit as long as it had the kent engine. Not sure that the outlet faces the right way but some of them contain a hole for the fan switch.
i think i have a couple about...i will have a look.
I have a few, I'll sort one out.