Adcom 535L upgrades?

The 535i is a well designed amplifier and responds well to upgrades. Do a search and you'll find a good bit of information about upgrade paths. If I remember correctly it was a Nelson Pass design. 
Here's one:
https://hoppesbrain.com/2015/06/12/the-super-high-current-adcom-gfa-535-ii/
There was an outfit that specialized in upgrading 535i but I'm not sure if there are sill in business. Worth checking.  

I’ve owned a few 535s and they always worked flawlessly and sounded fine. I currently use a later 5300 as a backup/satellite (outdoor speakers) amp and sold the last of my 535s a few years ago. The 5300 is 85wpc and in my humble (!) opinion it sounds far better than a 535, even the later models (5 way binding posts added instead of the twisty things they had originally). I may get the 5300 upgraded someday or fixed if the caps get leaky as it just works as it should. Great torroidal/mosfet amps costing very little relative to how they sound.

Thanks, guys. I do like it. Will report back if I find a local tech.

Musical Concepts/Musical Design may be a rebuild or upgrade path as well. They are not cheap but their work is top shelf. 

Thanks, llama!