I'm gonna come in on the other side here. The motor came with a 1-year guarantee. It's been almost two years. The motor builder's offered you 50% off labor. Seems fair.
You didn't do anything when you got the motor to negotiate a longer warranty. You didn't tell the guy it was gonna sit for 18+ months. Heck, maybe while sitting, something gummed up. Not his fault necessarily.
I'd say the motor guy made you a decent offer. Take it.
Cheers!
George
