Changing Engine Cases

Why not powder coat the ones you have, with Triumph prices that must be a cheaper option. The alternator cover is listed at £133 and the clutch cover at £250!!

 

Not sure what you mean by 'Triumph used to do a kit for this'. A kit for what? Changing engine cases from polished to black?
As Samsgrandad says, powder coating is going to be an inexpensive option. Or cerakoting, which can be done clear, so you could retain the polished look without the nightmare-to-clean, although it's not cheap. Of course check out ebay if you simply want to buy black cases, they quite often come up, but I'm sure you've thought of that.

 

Triumph did a chrome kit for the three engine covers but I don't think they ever did black?

 

Triumph do replacement engine cases in black for the T100,T120 Street Twin etc, for silly money, unless they've recently stopped. As I said they're not too hard to find on ebay. Motone make their own replacement covers.

 

I had a quick butchers on ebay, looking for Street Twin engine cases (as you know they're the same). There were a couple but as you said, they both had minor damage. I have seen them come up in mint condition, so they're out there if you're patient.
So it looks like your choices are to buy new cases, wait patiently for decent used cases, get yours powder coated or cerakoted (cerakote clear is not the same as DIY clear coating, this stuff is tougher than powder coat) or go for cases from Motone (which I have done and their cases are easily as good as the originals, but not cheap. I got mine during their last 20%-off sale).
If trying to keep the ones you have looking good is a pain in the arse, which it sounds like it is, then I'd bite the bullet and shell out the cash. Or be bike-less for a week or two while the powder-coaters do their job.

 

Maybe purchase some second hand to powder coat, so you can retain original and not have downtime??

 

Buy a tube of Rub n Buff silver leaf. Apply sparingly with an old toothbrush, leave for a couple of minutes, then polish. Stops corrosion on alloy cases.

 

I think Dartplayer has found your answer, well done that man.
I know insurance companies can sometimes be a bit uncooperative and some of them may try to wriggle out of paying-up, if they can show you've not followed their rules. But I can't believe any of them would try to get away with that particular excuse. Perhaps you were joking?