Before I start talking about vintage petrol pumps I will tell you how I first got into them. In the mid eighties myself and a friend Peter noticed that as the small rural garages were closing down nobody was saving the old petrol pumps, at first we purchased them at scrap value and were laughed at. We would buy anything that was pre-seventies and as there was nothing written on the subject learnt as we went along. In 1989 we took four restored pumps to a local vintage car show, not knowing what sought of reception we would recieve we were delighted with the interest shown. By this time we had formed the Period Petrol Pump Company with the intention of restoring and selling some of the pumps, after being featured in Practical Classics magazine things really took off. As the local supply dried up and I was traveling further afield to purchase new stock we took the decision to not to sell any more pumps, now we just hire them out to film companies. We still have about 175 pumps, all ages and all conditions, also I have written a couple of articles on the subject for Vintage Road Scene magazine.
When purchasing a pump make sure that it has been disconected from both the electric supply and the storage tank, both are specilist jobs and you might be responsible for "making safe" afterward, remember also that some hand opperated pumps had an electric supply for lighting. Pumps in as found condidtion are dirty, smelly and could still contain half a gallon of old fuel, when layed on it's side this will leak, vintage pumps can also be heavy!
It is up to you whether or not you save the workings, we leave the internals of pre-war pumps in place, later ones are gutted.
This is not intended to be a price guide, I believe that if you like something "go for it" if you are only looking for an investment ask your bank manager about an ISA.