Not so much a tech tip as a pointer...following lots of attempts to get a shop that would manufacture small, limited run parts (less than 5) I struck gold with the following people:

Neeco Engineering
2 Monk Rd, Somercotes, Alfreton DE55 7RL

https://precisionengineeringderby.com


Useful if you need something you can't buy or make yourself. They are very helpful.