Hi,  The bearings in the Duo-Art pump are a standard size and are
available from supply houses that sell these kinds of industrial
parts.  Google on "bearings"; I found a supply house in my home town.

Note: the "Made in USA" bearings are not cheap.  By searching on-line
I found that I could buy 10 foreign made bearings for less than a pair
of the USA-made ones.

So my rebuilt Duo-Art pump is running on a pair of foreign bearings and
I had eight more which I gave to a fellow friend rebuilder.  The bottom
line is that new bearings are available and my pump runs very nicely.

Note: I am assuming that you are talking about the main crankshaft
bearings, not any of the ones on the individual bellows connector arms.

Pat DeWitt