Onan generator repair cost

My generator quit a few weeks ago while I was on a trip. It ran all day but wouldn't start the next day. It looked like the carb was leaking a little fuel, maybe a crack or a bad seal or something. It needed maintenance either way.

This is an Onan Microquiet 4000k genset. "KY" something or other series.

So I just got my quote from Cummins.
$1616 for:
Labor + maintenance
carb rebuild
Cleaning of slip rings
replacement of the brushes

So I asked what the cost was for a new genset. That's at least $3500 plus costs for installation.

So $1600 starts sounding good, but I'm curious as to whether or not it's a fair deal.

I had to look up slip rings... Wasn't sure how "dirty" mattered. The problem wasn't a power problem, it's a small engine problem.

So first, I'm asking for just opinions about the price.
Is there anything else I should check or ask for?
Where do I find a non-Cummins repair place to get another quote?

I looked online and am having a hard time finding any kind of listing for shops who do generator repair.