Sounds like he mentions one brand , Velospec, that is possibly butted and heat treated in Taiwan.
If a frame is being made in Taiwan, then Reynolds, Columbus, Dedacciai can supply finished tubes to Taiwan...
Some frame builders still in Scotland:
https://www.brazin-scotland.com/
https://armourcustombicycles.com/
https://www.thevandalmetalworks.com/about
https://www.fivelandbikes.com/
https://www.facebook.com/KineticsGlasgow/
Shand Cycles appears not to be in Scotland any more:
Shand Cycles UK Ltd
Unit 2
Francis Street, Foleshill
Coventry, CV6 5BS
United Kingdom
01506 435 400
Anodising a bike frame can be difficult, even if it is new.
Knowing what grade of alloy, plus the grade of weld wire used is important.
The frame has to be clean etc.
This gives an idea of some of the issues with anodising ...