Greetings all,  As I pull apart my Simplex valves I come up with
a couple of questions.  First, is there an 'up' and 'down' orientation
for the aluminum collar on the valve stem?  This set seems to have the
concavity facing in on some and out on others.

Second, when installing these collars after replacing the valve faces
and pneumatic cloth punchings, was the original spot of fixative burnt
shellac, or hide glue?

Many thanks,
Skip Downing