Bought an older Generation C whistle earlier this summer and I’ve been curious about how old it may be. Is there a way of telling the age?
It’s hard to tell from your photo. But does your whistle head have
- A ridge line along the center, both top and bottom, running to the tip?
- An oblong dimple on the underside?
If so, then the whistle is pre-1985 or so, which is around when Generation changed the molds.
For ID purposes, a high-contrast photo of the underside of the whistle head is actually more useful.
The answer is yes to both.
Lucky you … you have a vintage Generation. 
I’m just going from fuzzy memory on the dates. I picked up my set of Gens around 1982-1985. But I think the store was out of the Eb whistle. By the time I finally completed the set within the next year, the mold had changed. So the change-over was right around then.
But if anyone has a more exact date, please fire away!
I have a Generation C like that. It’s verra’ naaice.
I have three Generations like that, a C, a Bb and a F and I bought them in 1989 I think, maybe in 1988 for the C and the Bb. The D I bought at the same time was made with the new mold, probably because they are the most sold. Stocks of the others (C,Bb, F…) had not probably been sold yet, in 1989.
The heads of my Bb and F are a bit broken now, but my C still sounds very good.
I have one like that lying across the top of this computer keyboard. I think it is the second whistle I bought in 1969 (the first was a high G and I soon learnt that it was socially unacceptable). I hope no-one is going to say that back in those days all Generations were wonderfull. Because I could only getr squawking noises out of it. In my ignorance I scraped the top of the blade with a penknife until if had a very sharp edge. It was thicker in the middle so it ended up with a notch at the sides and a protruding sharp tongue in the centre. Made it very quiet and almost impossible for me to keep in the bottom octave.
Now, my breath control having improved, I find it is easy to play quietly and softly. I have a couple of rejected Generation Ds (one with the same moulding) around and am wondering if I should try the same hack/tweak on those
Edit: Have been rummaging in the drawer. The 1969 G has the same sort of moulding (and a ding where it was attacked by an enraged sibling). It’s not as loud as I remember it. So it looks like that moulding was used for at least 15 years.
MTGuru: Thanks for your help w/ the ID. I’ve been wanting an older whistle to go w/ the newer ones I’ve acquired. It is a good playing whistle and was cheaper than a new Generation C.
If anyone has an old Generation D that needs a home, let me know… 
I found a matching Gen D on eBay (mis-identified). Fipple has been gnawed on, but it’s a nice sounding whistle. Are there any other keys from this time frame I should be looking for?
Nice. I guess you could try filling in the gopher gouges with glue or resin, maybe mixed with red dust from a sacrificed new red Gen head. I wonder if any of the whistle makers here have tried that sort of thing?
I bought my now-vintage Gen set from one of those Generation display cards with one of each key in nickel and brass. So I had no choice of picking the best, I just took what was there. And I’d rate all my Gens a good 9 or 10 for tone.
So no guarantees, and maybe I was just lucky. But I’d say any of the keys from that time would be fair game. 
I’ll keep the fipple the way it is, no need to be dabbling w/ chemicals. Was wondering, though, have you loosened the fipples on your Gen’s to make them tunable? Was thinking about it, but I’m also concerned about possible damage, since the older plastic might be more fragile or brittle.
It’s nice to know they did a full set of keys back then, gives me a different and affordable direction to go w/ my WhOA.
Oh, yes. Absolutely.