I have 2 now. A siphon and a gravity fed. Both inexpensive, and both doing alright. I use a moisture trap and always spray before I get to the project. I'm new to this but really like the shading I get.
I use one of those. The first one broke the frame where it meets the handle. The second one (replaced with no issues) has held up much better. Your's does look uneven. I'd try for a replacement. I put mine on the buffing wheel from time to time.
I tried the water based glues. Not as good for holsters. They seem to not hold very well when wet molding. I went back to weld wood contact cement. We also used the rubber cement on conveyor belts in industry. I'd use the Barge.. Do it outside if you have to.
I saw that video as well. Haven't tried it yet. Looks good! Yeah the stitches had an oops but at least it's on the back! Good job. That is the problem with large welts. Hard to keep the a alignment straight.