Must be the stout. I don’t think Guido would dare send me anything labeled “lager”. 
Seriously, IIRC the difference is in the voicing, not the bore size.
There’s a 3 character minimum for indexing, so “gg” will be ignored.
FWIW, I did a write-up on the whistles here: https://forums.chiffandfipple.com/t/guido-gg-whistle-clips-and-review/56725/19
thanks! 
I read this and realized that I don’t think I know exactly what “voicing” means. Could you elucidate?
Sure … Voicing is just the configuration and adjustment of the fipple geometry to tailor the tone and response of the whistle. The blade, window, block, windway, bevel; the sizes, shapes, lengths, etc. I guess the layout of the tone body and holes with respect to qualities other than strictly intonation could also be considered voicing. The term is commonly used in connection with the setup of organ pipes.
In the case of Guido’s whistles, IIRC it’s mainly the size/length of the window that makes the difference between lager and stout.
Part B: I’ve listened to the clip, and I don’t hear much breath-sneaking there. Where do I breathe?
BTW: Would this jig be considered more advanced? Should I set it aside for a while? It’s kicking my butt.
Well, referring to my transcription above … Look for the “z” rests in the B part. Those correspond to the breath points.
Nah, I’d call this a fairly simple jig. The melody is most straight arpeggios and step-wise.
MB … If you can post an audio clip, maybe we can identify where you’re running into difficulty.
Um…I didn’t know how to read ABC… [slinks away embarrassed]
But I looked it up.
http://www.abc-notation.com/introduction/index.html
Thanks!
Oops, sorry. No need to slink. 
Just plug the ABC into the [u]Concertina.net converter[/u] …
So the rests correspond to the z’s?
Yep! And, of course, rest corresponds to Zzzzzzzzzz, especially if you snore. 
Not the image my playing conjures up, though.
Okay, I just figured out the little roll symbol too. Duh. Makes way more sense now that I can see the notes.
That gives me some ideas for breathing, thank you. I think I’m overblowing too hard to compensate for those higher register squeaks + not confident enough of the tune yet to play variations on it. It’s definitely not “clip” ready (not that I have a means of producing one, to my knowledge–seems like every last electronic thing in this house has a glitch of some sort). Anyway, how could I embarrass myself thus after listening to yours? And hearing that it’s a pretty simple tune? 
More practice…
Downloaded the Alasdair Fraser version @ Amazon. Nice!