How to date a Denon DL-103

First real post!!!
I have a DL-103 and it's serial number is 3625.
The paper with the evaluation isn't on tracing paper and it has a blue coloured line representing the frequency response.
How old is this do you all think?
Thanks in advance!

Buy it a new headshell and tell it that it looks beautiful! :)

Geoff

Yours is from the early 60s by the sound of it https://en.wikipedia.org/wiki/Denon_dl103

Oh how old? Have you tried contacting Denon?

Geoff

I thought that I'd try here.
I bet you guys have more knowledge on this kind of thing than even the parent company.
I have two others bought last year and they have 5xxx serial numbers with parchment paper as the evaluation sheet. Also the colour of the damper is brighter blue on this one then the other two.
The puzzle is that this was bought new in 2015 but may have been old stock.
How old is what I wish to dertermine.
Possibly pre 2002 or around there?

I chose a dud topic huh?
Oh well.
There just seems to be little on this cart and how it's changed over the years. I have heard that the pre-2002 models have Alnico magnets in them and that seems to mean a whole heck of a lot when it comes to how the thing sounds.
Hopefully those with experience will chime in here with a bit more information than I have been able to figure out.

Interesting question so I decided to open some boxes.

I have two DL-103r. Both have traces printed with black ink on paper typically used for plotting such things. However the 'older' one which I purchased as broken about 7 years ago to have it retipped, has the number 8521 while the one I purchased s/h about 6 months ago ("It's new but I can't get it to track properly") and I must say it looks unused, has the number 1594. Incidentally, when set up correctly it tracks beautifully.

Interesting!