Exhaust heat exchanger advice

[bschwartz]

I'm considering the following if any of you think it would be a good match for the 6/1.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=220544933307&ssPageName=ADME:X:RTQ:US:1123

I asked the seller the dimensions, and he/she replied:

The length is 21" with a 2" exhaughst, the height is 9" and 9" across. the opening for the exhaust connection opening is 1 1/4"

[bschwartz]

I think the seller just called it the wrong thing.
They did indicate to another buyer that it has water in/out.  So I believe it is just a heat exchanger.
If it goes cheap enough, it might make for an interesting experiment.
New these units sell for around $750!!!