If its glass is 10in. in dia. its a 17, 13.5/8 its a 117.
If its 13.5/8 and does not have postive stops it could be 77.17 top does not have lights,which you didn't mention.
Pictures would help, but according to Jack Sims book doesn't make it worth more.External pump puts it on high end of the worth scale.
*Wanted Pierce Pennant Petroleum*