The Milwaukee Railroad had a lot of miles between stations in the west. So that each signal location didn't have to be visited every day they installed snow shields to help keep the snow from building up on the lights. These semaphores were common through out Montana & the western expansion?
I have created an oversize target with the snow shield to fit most 3 light N Scale semaphore signals. I used a Model Power Railroad Signal as the basis, but have another of a different brand it also fits.
This can be scaled for HO on request.