Glad it hit the spot
. But all kudos should go to the original poster in that thread – very clever chap.
IIRC I had no need to pin the 37-47, as on mine one of the original Hardinge banjo studs included a sleeve with long key onto which I could mount both gears rigidly together. Of course what you have on yours may differ.
Pretty sure I bought my 47 T gear – might be worth a hunt around for sellers unless you really fancy making it.
On the second question about the 37/47 – I think that's the case but am away from my workshop just now so can't get a visual reminder. Pretty sure I had the same question and scribbled something about it on the threading chart which I printed out to make it completely clear (e.g. which way round the 37/47 goes) – far too easy to forget these details if time elapses between set-ups… but it's easy enough to experiment and get it clear once you have the gears.
You'll also have spotted the photo of the set-up for 2 mm pitch on the second page of that thread…