Where to buy exterior trim?

Not sure what it may be called today, a few years ago it was called the roof termination trim.

Searching online I didn't find it by that name. Allrite has all kinds of trim but not that one.(that i found)

The last I bought, I picked up at Bontrager's in Michigan.

I'd probably try the local dealers next.

A simple way to clean that is to make a soaking pan out of aluminum foil. Pour enough mineral spirits in, 1/2 inch or so, to cover and wipe it off every 30 minutes or so until clean. Lets you do other things while the mineral spirits does the work.

The flat seam cover seems to be the hardest to locate
Bing 'RV aluminum trim' came up with lot of options. An rv dealer/repair shop would be good source- might save some on ship
On line just random pull to verify style
Ebay vendor

Cleaning old trim bit of effort-putty tape not too bad, simple paint thinner. But does take time.