The third digit on the serial number of cameras and lenses seems to show the year of production on lenses and bodies
(wasn't aware of this until recently)
Cross checking bodies and lenses I see a 0 on one Film 7 and a 4 with one which is also marked Konica Minolta
Dynax 5 film bodies one is marked 3 third digit on serial and also has Konica Minolta on the label, other is 1 and just Minolta
My 70-210mm starts with a 5 and the third digit is 1 so natural to assume 1991 production 1 also present on the 28-85mm, 9 on the 50mm F1.7 (1989), a 7 on the 35-70mm F4 (1987) and a 2 on the 24-105mm (2002), 7 on the 28-105mm (1997), 1 on the 100-200mm F4.5 (1991) and finally a 4 on the 100mm F2.8 macro D (2004). I have a few others around 18-70mm shows 5 (2005), not dug out the other stuff as that covers most of it.
Thought I would pass that one in case anyone is wondering. It does seem to tie up so far 100% with the lenses and bodies
Not sure if there is a way to tell on the Sony lenses and bodies. I know more recent bodies had a production date marked on the plate (ie month/date)