you will be well advised to walk away...
What's going to happen next?
The install weenies that are onsite at the factory are going to complain that the graphics are inferior, defective, wrong, and THEY will have to redo them anyway.
They blame you & your materials for a botched installation.
You won't be making any money on top of it all!
What is in it for you?
I do not understand how you got the gig to begin with. If the factory has in in-house graphics guy then how did the job even go out to bid?
Liek I said... I do not see a winning scenario for you unless you can get someone to let you do the job at your place. Maybe you deliver the graphics AND then bill them for the install anyway. If you have been awarded a bid/contract and they choose to use someone else anyway then they are still responsible for the contract.
If you have no contract in writing and it was just a phone call thing then you are screwed.
This is the same thing as a customer wanting a quote for 100 coro
signs but then ordering 6.