Does it hurt the value of a vintage gas pump to remove the electric motor and pumping unit?
There are several "right" answers to this:
1. Removing the guts lightens the gas pump assembly making it easier to move. It also eliminates most of the smelly and possibly hazardous gasoline residue.
2. Leaving the guts in pumps left outside makes them tougher to steal and more stable in strong winds.
3. Leaving the guts in visible pumps provides a place for attachment of the outside handle and gives some low weight to help with top-heavy instability.
4. If a gas pump has an unusual or rare pump mechanism, it would be prudent to leave it all together for history's sake.
Except for the situations mentioned above, it doesn't hurt the resale value of a vintage gas pump to remove the guts to all but the most purist collector. Removal also makes a pump more compatible with displaying inside a house.