Having worked with tower grounding and AM transmitters the bonding of connections are important in both RF (Radio Frequency) and AC power. Often a compound called Penetrox is used.
PENA134 - Burndy - Electrical Joint Compounds | Galco Industrial Electronics
This will eliminate corrosion between dissimilar metals and provide a electrical connection between cleaned surfaces. This is available at Lowes or Home Depot. We used a lot of alumium connectors for high power 600 vac 500 amp services for UHF transmitters and always used penetrox to eliminate heating and damage.
One bigger question is code surrounding Neutral bonded to Ground. According to Ontario and Canadian Electrical code a sub panel can not have the neutral and ground bonded. The park service panel distribution is where they are bonded. The National electrical code in the US may be different and the trailer have CSA for Canadian Certification. There is the code that says no and the reality the Trailer is safe and meets code as per the CSA certification.
The outlets in the trailer are protected by GFCI so the bonding from a safety aspect might be a non issue but hot skin or what Lou had could still happen as the return ground path is on the neutral instead of the ground. With high power usage in a park, all being single phase, it is quite possible a lot of neutral current exists creating a AC potential between the bonded trailer ground and real earth ground. When I spec an install I always have double sized neutrals added to compensate for single phase loads.
Sorry for going all engineer on you with this