Late in 2010, ABB supplied new E-Stop switches to replace the original ones made by Baco. While ABB did a pretty good job of suppling new switches to registered customers, many did not get their switches replaced. While ABB supplied the switches, the customer was expected to install them. The replacement campaign ended after approx. 1 year. After that, you had to purchase yourself.
Over time, most Baco switch contacts suffered from dirty contacts that would occasionally cause run-chain issues. There were also a few cases where the tabs broke off the the switch carriers allowing the contact blocks to disconnect from the switch actuator - not good!
Attached is the parts list and the procedure from those kits sent out back then under SI10203. It contains the part numbers of the new replacement switches (ABB switches of course) along with instructions for M92 thru M2000A pendants and controllers.