That is not as daft as it sounds, I am coming down to the South Coast with someone who wants me to give a boat the once over before he buys it. Difference is he is paying.
The tea bags are tempting though.
I would have a look at the solenoid on your starter motor. They have a couple of copper wedges inside them that get burnt and corroded. If you can get into them they will clean up with emery or a fine file. A way of testing is to use a jump lead from the battery direct to the terminal that connects the heavy lead to the starter. If it spins normally the solenoid is duff.