Nikkor SW 120/8 - any evolution within last 20 yrs?

[Torsten]

Hi, I'm considering purchasing a pretty old (1988) Nikkor SW 120/8, and I wonder if someone knows whether there was any evolution of this lens in the last 20 years?
Btw, do you know where I could find Nikkors LF serial number / age listed?

Thanks a lot
Torsten

[LH1H17]

Older samples will have a five bladed aperture in the copal 0 shutter, where as newer ones will have a seven blades (marked "(s)")

as far as I know the glass is the same...

and one more thing to check.. there should be a thin metal shim between the front element and the shutter on this lens