My understanding...
The anode is one metal protecting another. The protective metal (anode) has to be less noble than that which it is protecting.
Stainless steel is pretty noble, so it will quickly cause an anode to dissolve. The stainless is protected by the anode but decent stainless steel...
Waterproof toolbox fixed the problem for me; no need for WD40 etc.
I use a Stanley Fatmax - https://www.stanleytools.co.uk/products/detail/Products/STORAGE/Tool+boxes/STANLEY®+FATMAX®+Structural+Foam+Tool+Box
Shop around as prices seem to vary a lot.
I would imagine that the screen frame is made from a series of fairly standard extrusions if it's a flat glass screen. My aluminium Fletcher one certainly seemed to be made in that way when I took it apart last year. The rubber inserts are also fairly standard. I got replacement rubber from...
I think the big yards/professionals that have the necessary equipment spray & the small yards/DIY do roller & tip.
Spray gives a better finish; roller & tip supposedly more durable.
(I'm thinking about doing my boat (DIY). I was going to try re-gelling but my research seems to show that roller...
I believe the technique used is called roller & tip. The paint is 'leveled' post roller whilst still wet by dragging a thinners soaked brush along it. Can give a pretty good result if done correctly.