I also had a similar problem with an Ampico I once rebuilt.  To remedy
the situation, use the correct size leather washers, but pound them
slightly with a hammer before installing them.  This will flatten and
expand them a bit, and when installed they will be compressed slightly
and should seal properly.

The take-up spool should spin freely when the lever is set on rewind.
Ease off the rewind brake.  I have mine disconnected, which prevents
roll damage during rewind.

In addition, I seem to recall a stem on the take-up bearing that had
a hole worn in it.  Check for leaks before you put the spool back in
place.

Bruce Clark