My project involves the gut rehab and selective demolition of a historic structure. Due to damage caused by water leakage, the existing roof deck will be removed and replaced leaving only the structural timbers behind. The existing slate will be sent off-site for cleaning and restoration. After cleaning and restoration, the now reconditioned slate will be reinstalled on a new roof. Can I pursue MrC3 for the slate?

On the one hand: due to deterioration, the existing slate can not be reused in its original purpose, without extensive off-site restoration; and its original location no longer exists. On the other hand: in the finished project, it is ultimately being used for its original purpose; its functionality having been restored, albeit in a new location. While the material had to be transported off-site, I dont think I can go for the off-site exception; since it wasn't originally found there.

Any advice?