The location of the rewind valve in an Ampico B is in the left
side of the drawer, and is the top left valve on the valve block.
You can't miss it.  The chances are good that either your valves are
not completely restored, or that your reroll tube is clogged up or
pinched off.

I would suggest to first remove the little 5/32" tube coming to its
pouch nipple from the 8T hole in the trackerbar and blow through it.
Watch what comes out of the trackerbar hole!  I'll bet you get a small
cloud of dust!  Don't try sucking it out from the trackerbar.  When
they get this bad, you have to disconnect the tube first.

Craig Brougher