>The symptom I am experiencing is lack of cranking power after the engine
>has been running (hot) and is shut down. The engine hardly turns
over....and I
>often have to wait 3-10 minutes before I can get the car started again
Try bypassing the starter solenoid with jumper cables. Check all wiring, including ground strap to the engine. Are you using an alternator or generator? Make sure it is charging your system adequately. I once came home from a long night trip, stopped the car in the driveway to open the garage, and couldn't restart. The generator had not been keeping up with the lights, heater, radio, etc., and the battery ran down. An alternator is a wise mod. 'Haven't had that problem since (I have other problems). If you're unsure about the starters, you could have them bench tested at a starter shop.
Have you checked your ignition switch? Sometimes these will heat up under load due to poor contacts. Try bypassing it to see if you can start the car when hot (just jump from the main hot wire to the ignition switch wire at the solenoid). If so, replace the switch (those "inferior" British electricals don't last more than 25 or 30 yrs.).
Starters draw many amps. Make sure the cables leading to the starter, solenoid, and battery are sound, and capable of delivering lots of current. Look for corrosion and poor connections. Replace them if there is any doubt.
Good luck, and let us know how it goes.
Rex Funk