Anyone Know Anything about the Value of a Rutenber Engine from the Early 1900s?

Good morning Mr. Heitmann, 

I have recently acquired a defunct early 1900s horse drawn fire apparatus.  On this apparatus is a Rutenber 4 cylinder engine.  I'm interested in any information you may be able to share about this engine and or apparatus and would like to sell it, preferably to a museum or collector that will restore and preserve the engine for future generations.

From my research, I've found that the Rutenber engines were used in Howe Fire Apparatus in the early 1900s.  The serial number on the engine is 7663 so I'm thinking it's an earlier version but again, can find very little about these engines online.  

The block appears to be aluminum with steel exterior cylinder heads.  The heads are pretty well worn.  There is lots of brass accessories and fittings on the engine that are still good.  I haven't done anything with it since I got it so I'm not sure if it's locked up or anything. 

I haven't been able to find any Rutenber engines on the market at all.  I do know that one was donated to the smithsonian back in 1973.  Any info, including an approximate value would be greatly appreciated.  I know value is going to be very subjective due to the lack of past sales information as well as the condition of the engine, but I do know it's extremely rare.

If you prefer to speak about this over the phone, feel free to call me at 336 317-0504.

Thanks,

Rick