Great source Andrew (once I sussed out you meant PdF pages 79/80: pp75/76
). There's a lot of useful old texts like this out there (if you can find them).
I note that Peck's request (which was granted) was that the Regt retained not only 'highland garb' pipers but also the 'bonnet cocked' (presumably the kilmarnock/hummel... with or without feathers?) . At what stage this evolved from this into the taller, stiffened, shako like peaked headgear shown below is unclear but it seems to have happened by 1815 (perhaps this is the pattern referred to in Pack's memo of 1810?).
The evolution of the bonnet (in fact No4) from low-ish pillbox style to semi then full feathered and the 71st's Kilmarnock shako (No5). The green pop-pom on the top isn't visible (Miro's plates show this better).
This PhD thesis explains about the development and manufacture of the hummel (with photos of just how tall and extravagant they got in Victorian times)
Regarding pipers and sporrans: this is supposed to be accurate (from Vimeiro, 1808 so they are in the pre-1807-1810 tartan trews and also full feather bonnets): note the wounded piper in full highland garb including sporran (and you can almost see the answer to the proverbial question*).
Circumstantial I know, but in his memo (see extract above) Peck makes much of retaining regimental tradition, honour and esprit de corps and, assuming that his Colonel (Francis Dundas; Col 1809-1824) felt the same, it would seem to make sense that they hung on to the full-fig pipers as long as possible (Stadden still had them in kilts (and sporran) in 1828- see below).
Nap's ref shows a 71st piper in 1806 (so still the kilted Glasgow Highland Regt) and alongside is the pleating of the sett plus Stadden's painting.
According to Franklin this was the uniform between 1793-1815:
There's a
re-enactment group here (but they don't seem to have a piper):
*what does a Scotsman wear under his kilt?
