Welcome to Ribnet!
It could be a good buy, and the tubes may only need new valves, or ifg you're really lucky, new rubbers for the valve caps. It could be that simple.
I would guess the trailer is not going tobe much cop.
The engine is also not likely to be reliable, and I would be thinking of changing it.
Can you post some pics? Very fdifficult to make useful comments without them, or at least without more details.