spit - softtop body snap?

[Michael Galloway <mgx@icesar.epm.ornl.gov>]

here is another one. i ordered several replacment male body
snaps for my spitfire along with some rivets. what came in
the box were these little bitty brown plastic things that
look to be about the right diameter but look pretty thin.
should there be a washer or some such thing install under 
the snaps? the catalog shows using washers under the two
snaps nearest the doors, but i assumed that was to account
for the trim piece there.

-- michael galloway
   '78 spitfire