This is a great amp, worthy of fixing up
I spent about as much as you did in 2021 to refresh my MKII.
Absolutely worth the investment.
The factory set bias of 40 mA will allow approximately 16 watts in Class A and, yes, it will be warm at idle but not hot. Unlike the Threshold's of that era where bias was set at 100 mA allowing 25% of rated power to be in Class A, however they were hot to the touch at idle and component reliability/longevity suffered greatly.
My tech also prefers the the MKII vs. the original and prefers the Naks over Thresholds for build quality and component selection.