Hey Joey how are you, when you say you're talking about the fireground with Trenton, if you're talking about Simplex frequencies that are low power as far as I know they don't use them. The last time Dan and I went up there to try to confirm this we could not find them being used. Fireground is going to be F2 F3 ect... and they will start with F2 first then go to 3 then to 4 depending on how many different calls they have.
460.575, pl 103.5 has been rebroadcasting Trenton fire for well over 20 years even back when they first went digital in 2000 and before that it was actually their Fire frequency when the police were on 460.60...
Philly DJ Dan and I had mapped out the NXDN system in 2015 and used laptops in our cars with DSD. Of course the police were in the clear for five years but always said if a certain thing was to happen they would go encrypted, it did, and they are now encrypted.
The last time I checked out the database the frequencies were wrong. They made a lot of changes on the State Street and Hoffman Avenue sites. I was retired by then and didn't care to research what the new frequencies were as all it would be for would be fire, dog catcher, DPW, housing inspectors, Water Department Etc. F2, 3 4 Etc, it's also rebroadcast on UHF fire. There are some frequencies that are administrative that they do not repeat. Since we don't have the right frequencies anyway I think you are best just staying with the UHF rebroadcast.
It is a really crappy system, the nxdn, I don't think you would get both sites anyway knowing your difficult RF environment, you do need to pick up both sites so as not to miss any transmissions. I don't think I would waste the money on the upgrade.