Earliest that I have is Serial number B 10684.
FF85 8.5' 3-3/4oz DT6F-HCH
Interesting the mix of AFTMMA Wt and old silk Letter (diameter) . The HCH would roughly cross reference with a DT 7.

The rod is gorgeous, pristine and even the sock and cardboard tube are intact and in amazing condition for an almost 60 year old rod.
Lawn casted and it is sweet. Going to load it with a 1/2 size heavy 6wt WF Stillwater line and baptize it this weekend with swamp water, fish slime and bug guts.

Will also take out my FF85 8.5' 4/1/8 oz 7-8-9 Serial Number E 44205. (Funny how in three years this model changed so drastically)
Translucent but not as pretty. Going to use a 7Wt Bonefish Quickshooter. (Box says warm water saltwater, but who cares what the manufacturer says. It also says 7wt and we all know that is not accurate either. Closer to an 8.5wt.) IMO one of the best summertime bass tapers.
But I didn't buy these to admire. Both are going to catch bass and get dirty and dinged by end of summer anyway.

Will probably also take along the FF85-5. No serial number that I can find. Same period. Labeled "Voyageur" this one is a 4-1/8 oz also but 5 piece. 8 wt.

I am curious why this travel rod is not in the wiki and all the other ones are. TheFF80-4 and FF 86-5 Voyageur is. There is even an FF85-3 but not the 5 piece.

That change is interesting. Not sure when it was done. My FF85 is an “E” marked only with the rod weight of 3 3/4 oz. I’ve primarily fished it with a DT7, and think of it more 6 than 8.

I’ve wondered whether when they increased the rod weight, they then decided to produce the FF86.

A quick clarification and question.
When I made my list, I had my FF756 as a 3oz when it is really a K serial number 3-1/4oz.
Now the question, the first rod I bought was a FF756 S series. But it was labeled a Fenwick Woodstream and was upset and disappointed. I thought the seller misrepresented it and the photos were blurry. After that I always made sure I could clearly see the label, wt and serial number or requested from the buyer before I bid. Now I am wondering if these Woodstream versions are considered part of the 2nd generation. The rod actually casts pretty well for me. Maybe a bit faster than the other Fenwicks I have. Thoughts?

Thanks for the clarifications. I am more about fishing than collecting so it sounds like I won’t have to worry about the labels or serial numbers on the 3 digit models. Just research what others have say about the characteristics of the different models.