I had also heard that old guns (I don't know what vintage) were labeled "E" for economy and "D" for Deluxe.
However I don't know this to be true...could be an urban legend.

We all customize our rifles so much, perhaps we could come up with our own system:
For example, I suppose could say I have a Stevens 200 BTVSJB3PDNSEGWLBH.

However, it is usually faster to simply describe the rifle than to try and remember the Savage (and my totally made-up) lettering system.

BT (Laminated Thumbhole)
VS (Varmint countour Shaw barrel)
JB (Bedded with JB Weld)
3(Three-screw trigger)
PD(Pachmayr Decelerator butt pad)
NS (No sights)
EGW (EGW20 min rail)
LBH (Large Bolt Handle)