Mamiya RB67 year of manufacture codes

Hello all

Long time RB67 owner/user. The production date codes are 2 letter codes on adhesive stickers/decals. At one time I was able to find the way to translate 2-letter code to year of manufacture. I have looked on this and other sites without success.

Can someone please point me to the translator for 2-letter productions codes and year of manufacture? Thank you.

For my RB67 Pro-S system I have the following codes:

120 roll film back: HF
6x7 rotating back: EJ
Pro-S camera body: EK
Sekor C 90/3.8 lens: CL

mamiya stamped serial numbers at random. its possable to also find duplicates.

the series codes can be dated... there are charts if you google it.

http://rb67.helluin.org/lenses/

Thanks Paul. I spent some time on that site and didn't see production date information. Is there another link? Thanks again.

I responded on photo.net, but here it is again -

If you read through this:
grahamp.dotinthelandscape.org/mfaq/m_faq.pdf
on pages 21 and further, it appears as though it's a lot of guess-work to determine the manufacturing dates of Mamiya equipment. That pdf is mostly about the TLR's, but I'm pretty sure you'd be able to apply the theories to any of the Mamiya models.