Sell it as a show bike or off road track bike, with no warranty EXPRESSED OR IMPLIED.
But that wont stop any possibility of a future lawsuit. Most shops are required to carry liabilty insurance for work performed and often as a requirement for obtaining a lease .
It is all risk based, higher the risk, the higher the rates, and they will have no problem finding something to bump the rates, do you weld..yes (higher rates) Do you paint ..even higher..in this town now to put up a legal booth, between 20-30 K!!Heaven forbid you even mention the word brakes or front end.. that will often bump the rates so much that in some cases you are money ahead by not doing that work..
Which brings me too, work that did not happen...
You want say a caliper mounted or a brake thinned.. so you find someone that is capable or does it often. However there will be no recipt or payment by cheque..if you want it done. That or..your disc is billed as turn down thickness of weld-on pipe flange.. or something similar.
So basically the condensed version, you buy some liabliity insurance and hope it is enough to pull you through.. or face the prospect of getting sued for anything you own if something goes wrong.. good luck.. its tougher now than it has ever been..