Replacing MX with a 6NZ Cat

Has anyone sold or knows of someone selling a 2016 or 2017 579 Pete that has replaced the motor with a 6NZ recently. I lost one almost 2 years ago that laid over and had it under insured, had a 2016 catch fire on June 9th and still fighting with Insurance. There is I believe right at 860,000 miles on truck and just a little under 200,000 miles on this rebuilt motor (Cat platinum overhaul kit) 3406E 6NZ C15 600HP 2050 LBS/FT Torque 13 speed transmission truck when I ordered this I put just about everything I could in it. Tires at 80% there first offer was 38,500 2 weeks ago and they just called and offered 48,750 or 45,000 and I and can have the truck back. I need some more info to prove they are way under value of what this truck is worth

and would buy this truck back just for the motor it really is not in that bad of shape. or if anyone is interested in it let me know I'm going out of business, thanks much I also have 379's from year 2004 to 2007 for sale that all but one have recent rebuilds 1) 2015 389 6NZ Cat Platinum overhaul I believe just over 100,000 miles on rebuild also 29 reefer trailers ageing from 2015 - 2019 THANKS MUCH