Nautilus Serial Numbers Explained

This is a very nice 2nd Generation Nautilus Duo Hip & Back
This is NOT the serial number, but rather a sticker placed on the machine during assembly.  It does include patent/patent pending numbers, but is not relevant to the manufacturing date, and could not be used to order replacement parts.
This is a closer picture of the tag.
This is the serial number.  They were stamped and welded to the machine.  Usually under or near the weight stack.
DHB obviously is the abbreviation for Duo Hip & Back
The XXX were space holders
V indicates Virginia Manufacturing facility
04950 states the number of this unit produced within the production run

This is another serial number.  This time from an Abdominal I (aka 1st Generation)

 
This is a better image of a sticker.  This one is from a Bench Press III.  Although a favorite machine of mine, there was no way that Nautilus sold over 100,000 of these.
This one is from a Next Generation Adduction/Abduction combo unit.  As you can see, the plates were now pop riveted onto the machine (again usually near the weight stack), but now the year of manufacturer is included.  So this was the 43rd A/A machine made in the Virginia facility in 1996.
Finally, we have a 2ST bar coded serial number.  2FWN indicates 2ST Four Way Neck.  The remaining info is the same as above.  These were placed in many different locations on the machines, but check under the seat first.