Erich,
I used to be a product engineer for a company importing medical devices (hydrotherapy tubs) from Sweden into the US. Part of my job was managing the UL listing on those products.
You may or may not have problems with your equipment as is, it is hard to predict. We had many products that we imported without change using all European electrical equipment....other equipment had special provisions for UL.
I suggest that you submit the product for approval without change. Just be ready to respond quickly to the changes requested by UL. If your company or your customer has no experience with this you may want to consider finding an expert to advise you.
It can get very expensive if you have to go through multiple test cycles to get approval.
Good Luck,
GJ