Hmmmmm. Could you please give us the dimensions? I have an idea...
FYI...I have a working metal-based 30 and it heats and runs well.
An extra heater might come in handy. As to the value, there are probably
not that many model 30's out there at all and even fewer needing a heater.
If you really want to find out, put it on EBAY with a buy-it-now or best-offer
listing. That should do it.
Good Luck,
Wayne