Art

For big heavy leathers, I prefer Bob Beard's edgers. For everything else, I use Ron's.

You want the 16x2. Here's a list of needles you may want to consider from the thread exchange. https://www.thethreadexchange.com/miva/merchant.mvc?Screen=SRCHFA&Search=16x2

For size 33 (commercial) thread like I use on boot tops, I use a size 14 needle, but anything from 12 to 15 might work.

You want 16x2 or DBx2 for that machine. That number is called the "system". Then you need to pick size (generally the diameter of the needle) based on the thread you are using.

Try going up one needle size. Art

These are often called Martengale Hearts.

Well, you certainly made that clear in your original post. Lay part on a piece of grid or graph paper, both sides to be clearer. Now, call OTB and see if they can source what you need. They might not have it, but they can point you in the right direction. These can also be custom made. There are a lot of vendors out there, it might take a few hours on the phone to get a lead. Also, go to your original supplier and ask where they sourced them.

Fact of leather life here. Robert Beard tools sell for more than you paid for them when new. This is on eBay. They seldom come up unless someone dies. Barry King tools can be a little more flexible on price, but they hold their value too.

10 Seconds. https://www.amazon.com/Solid-Brass-Heart-Rosette-Concho/dp/B07BYYPYG1

https://www.amazon.co.uk/Aquilim-315-dispersion-adhesives-500g/dp/B00DJ3KHSA Renia Aquilim 315 it works very well. Water based, no VOCs. I stayed away from anything like this for the longest time. This is all I use now even though I have a gallon of Master in the shop.

Bite the bullet and buy a Robert Beard or a Henley. If you don't like it, you can put it up on eBay and get more than you paid for it. Both of those brands lean more toward being a "generic" swivel knife while being very adjustable for length. When you get enough experience to know if you want a bigger or smaller knife, like I said above, you can recoup your cost (hell, I'll buy it from you).

Email one of the older folks at Ohio Travel Bag. But a little searching can find it here: https://www.fasttech.com/product/9617220-boyou-b910-zinc-alloy-keychain-car-key-ring-holder

Those machines are very robust. They travel to shows many times a year over 1000 miles each way. If you can afford the needle positioner, get it. It makes doing cartridge loops a bit easier. You can live without it though. Call me if you need more info. Three zero one eight four eight seven eight one zero.

Isn't that a chain stitch machine?

.364 CRC Standard Math Tables.