I've had one since about 1985 and used to run it with a number of preamps and yagis. They work nicely, but the electrolytic capacitors will degrade over time to the point where noise degrades signal and there is inadequate voltage to drive the display. Lots of write-ups on the issue and, if you're handy, you can keep that thing working for a long time. I just changed the capacitors in mine recently. I forget how many times I've done it, maybe 4 or 5 by now. Sadly, by me, everything's gone to 800 and/or digital. There's very little to listen to in the VHF or UHF bands down this way.
For the heat issue, you can place a very small fan by the rear louvers, or mount a heat sink (with thermal compound), or both. I'd hate to knock holes in something unnecessarily.
Enjoy!