Of course, I'm not just going to make these windows straight off the bat. I have spent many hours looking into this project, looking at what tooling, hardware, timber, glass, adhesive, sealers, preservatives, paint are going to give me the best result I can achieve. 
So far in terms of tooling I've only had to buy a handful of router bits (including an 8mm spiral upcut bit which really is superb) and an 8mm router collet. I did treat myself to a new compressor off ebay so I can use my brad nailer. That had been sat in it's box unused for about 5 years, 65 quid, yes, get in there.
Apologies to anyone expecting some wood action, I am getting to it I promise.