I have never seen a
Scamp blackwater tank caulked in place. The P.O. may have had the leaking issue. The tank is installed with 4 lag bolts or screws and a wax ring is set around the exit hole. The wax ring is to keep shower water from running out the pipe exit hole. The only way to remove the tank is to cut off the tail pipe and replumb the 3" drain line. The tail piece screws into the bottom of the tank for removal and inst. It's best to order the ABS pipes from Scamp before you start removal.
You need to pull the toilet to find the leak. If the tail piece is leaking the wax ring prevents the fluids from entering the shower pan it will leak to the ground. The tank is made of a plastic which not much sticks to it so If it were mine I would consider replacement. You can order a tank alone.
Now the next issue, Scamp is currently using the 711-M28 Sealand Dometic toilet and tank. The older trailers not sure when but around pre mid 1990's had 911 Sealand's. You need to figure out what toilet you have.
The 911 will bolt to the new tank but it wont fully flush due to the flush lever hitting the tank. You will have to modify something to make it work or order a new tank and toilet. There are threads on 911/711 tank issues.
Eddie