Please take a good look at the ID tag for the Model number. I believe I have every thing that Bennett ever made on my website and I don't list a 968.
If it is definitely a 968, please post a picture of the pump and I will try and identify it.
In the meantime, please take a look at my website,
http://petrolianacollectibles.com/bennett%20pump.htm especially the 900 number pumps, and possibly................wait, just saw that you are in Canada, sorry but Model numbers used here in the U.S. are generally not the same as in Canada. Hopefully someone in Canada can answer your question.
Jack Sim