A very minor change was made in this reel. Please carefully take a look at the number 4 on the dial plate of the mechanical brake system on the left side. In this reel (#96XXX), the vertical bar of number '4' is so short that the top part is open.
Older ones, however, has a number 4 with a closed top (this is a scan of #54XXX). I'm not sure when they changed it, but it is a key to see how old your reel is.