Really. All naugahide but I’ll try leather soon enough. Took a couple hours. This was for Bb so it was the largest size. If you can make a reed you can make a bag. If you can dodge a wrench, you can dodge a ball.
The stitches were pretty horrible at first, trying various approaches. I settled on pushing the needle with the front of my (buttoned) shirt, it was heavy enough to drive the first needle through. You need round needles, a smooth-jaw pliers to pull the needle through - sometimes you can get it through by hand. You need to add extra stitches at the ends, to tighten things up. Look at a good sewn bag for guidance. $10 in naughahide, $5 in twine and needles. Oh, $5 in beeswax/oil. Bit cheaper than paying somebody $175!
I use a leather Awl
http://www.texasart.com/store/view/003/group_id/3543/Tandy-Leather-Lockstitch-Sewing-Awl.htm
Saddle stich is the way to go IMHO.
Here is some freshly typed advice, anybody have more to chip in? An accordion repairing friend of mine thinks we should be pouring in molten silicon compound or some such material - he’s dealt with many an old squeezebox with worn out beeswax (to hold the reeds in place) that’s given way.
" Hullo Jack,
Nothing magical about bag dimensions, just trace your bag onto leather or naugh and make the outline larger if you like. You should take your original bag and season it - hot melted beeswax/neetsfoot oil (or lard AKA Crisco) works, about 4:1 ratio. Just add a little bit of the oil/lard to the melted wax, pour in through the mainstock cup - remove blowpipe and plug its stock of course, same with the chanter stock - swish it around, inflate it and press the inflated bag - this will drive the seasoning through the stitches. You’ll have to remove some of the gunk later, attach a piece of cloth to a stick and fish out the seasoning. It should be semi-solid when it cools - if you add too much oil it will be slimey and come through the leather. You can test it by sticking in a cold knife first if you like.
Re-tie all your stocks before bothering with seasoning. Denis Brook’s Union Pipes book explains what to do.
All the best of luck you’re gonna need!
Kevin"
I think Cillian O Briain uses silicon compound to season his bags…Or at least he used to…
Others favor a combination of neatsfoot oil and melted beeswax. There are plenty of pros and cons to both these methods that I will humbly let others on this board bitch about.
Some Highland pipers season their bags with plain ol’ honey. Anybody out there tried that?
I used to use a combo of honey, glycerine and scotch(or listerine). It worked quite well. It doesn’t go rancid like the commercial stuff.
Marc
scotch tastes much nicer though 
So, Kevin, is it airtight? Did sewing it rid up your hands? I’ve heard it can.
Marc
Pretty airtight, as good as my leather bag. It wasn’t a strain on the hands.
Kevin, did you use contact sement, or etc… I use the same stuff as David Daye 3m 5200 marine vinyl adhesive, and I never sew a seam… I’m going to try this as well as I think the sewed seam looks better.. I’ve made a few leather bags sewed with an awl, but have never tried sewing vinyl… 
I not certain sewing vinyl is a good idea.
Kevin, I hope you didn’t use that stuff!
At least he,d always have a supply at hand !!
RORY
kevin, you may want to try a “sailmakers palm”. you wil probably still need the pliers to pull it through, but it can really speed things up.
I’ve put 2 bags togather with 3m 5200 regular(slow cure-7 days) and they are holding fine. don’t ever use goop, it creeps. I will probably never sow them as they are doing so well, should they fail, I’ll sow.
best, tansy
I took measures from my old bag, went to local shoemaker , bougth a good piece of leather. Cut and glued it ,and shoemaker maked the seam as I want it,(with machine, leatheredges turned twice ,and then put all together with heavy waxed nylon stuff.
It took few hours , all costs about 45 euros.
(Now just putting all parts together, cut the holes etc.. but that is the different story)