My '64 220SEb--Sudden loss of power, uneven idle.

[rusty_parts2001]

For the most part, this has been a reliable car for me. I don't drive it a lot (maybe 500 miles a year at best) and I've had it for 6 years. It is a manual transmission car.

The issue I have lately is: When I am driving it, after it has been warmed up, maybe like for 15 minutes or so, I suddenly experience a loss of accelleration, like the car is starved for gas, and I have to work the gas and clutch to keep it from dying, then it will run OK until I can limp it into my garage (since I don't want to be stranded someplace). Both the fuel filter under the hood, and the fuel pump at the rear are new. I've replaced both myself. The points and distributor are original from when I got it. I changed the plugs recently. The PO was a shop mechanic at a MB dealership and maintained it well, including rebuilding the engine about 70,000 miles ago. In other words, it was in excellent mechanical shape when I got it, and hasn't been used much since.
Any ideas on the diagnosis of this symptom?

The second problem is possibly related, although it never bothered me much. At idle (like at a stop light or sitting in the garage running after its warm), the rpms fluctuate between 500 and 1000 rpms. In otherwords, it has an uneven idle after its warm. Any ideas on that one?