Double Bass Strunal bass serial number

[fretless1369]

Just picked up a very nice Strunal 5/20 upright. I'm trying to find out the age of the bass and have not had any luck searching on line. It's serial number 02090350. Anyone know where to look?
THANKS!!

 

[ToR-Tu-Ra]

I don't think mine has a serial no. (same model). Where'd ya find it?

 

[fretless1369]

There's a paper tag on the inside glued to the back easily seen through the soundhole. Maybe yours fell off and is laying somewhere inside?

 

[ToR-Tu-Ra]

The tag is there, only no serial.