I have had my counter tops in my personal house painted with Rustoleum Countertop restoration for over a year, heat does not affect them, it doesn't scratch and it is not chipping even with 2 children under 10.

You could itemize the work into specific areas such as painting, electrical, carpentry, roofing, drywall, flooring, appliances, caulking, plumbing, trim, siding, etc. in order establish the amount of work involved in the restoration.

Habitat for Humanity Re-store?

Some of that awesome detail is going to need restoring and if you really want to restore it to its former glory, its is going to cost a lot more than 40K.

They often have to have a safety inspection by code enforcement before power will be restored, and often there is so much garbage and vandalism but they are not condemned.

Our local Habitat for Humanity Restore often has newer furnaces that have been removed from properties being razed.  

If it cannot be restored to its original condition then I would dock their SD or charge the rental account.Of course, that is my interpretation.

We painstakingly restored the outside while gutting, reconfiguring and modernizing the interior.

If I was buying a restored 1949 Oldsmobile I would want to see the before and after because I expect something that old to have gone from bad to good.

We did one in a SFRThe finish barely survived 18 months.But if its fiberglass I have seen an auto repairGuy I know do some great work restoring color.Good luck....