You never stop learning. Work got in the way of buying this, I hate when that happens!!. Great shape. What is a 402??...Doug
http://www.ebay.com/itm/321306326303
Don't know but it does have a special handset plunger, on one side.
paul-f has one about half way down the page
http://www.paul-f.com/we300typ.htm
It's an exclusion plunger for "single line with exclusion key (plunger lifts), for 1A1 or 1A2 KTS" use according to paul's info.
Here's a direct link on the page:
http://www.paul-f.com/we300typ.htm#401 (http://www.paul-f.com/we300typ.htm#401)
Of course, there's a lot more detail in the referenced BSPs.