The wrinkles never came out of my seat.

A few days of setting the timing of the machine left me mentally drained. It turned out some combos of thread, needle and material just don't work. This is true with fabric sewing. But I've found empirically that everything is much more sensitive when sewing leather by machine. There is a very narrow functional space where everything works and you get good looking stitches like those on luggage and car seats.
On another note, today I bought the Harbor Freight Tools Sewing Awl I mentioned here. I needed a gift for a frugal friend of mine. Being able to make heavy sewing repairs is a great money saver.
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It's funny because the one I bought from HFT in 1993 for $15 was a Speedy Stitcher made in MA. Now they sell this Chinese copy for$5.99. I used their 20% off coupon and it came out to $5. I was a little shocked at the low quality. Though the tool is lower quality it still works. Well enough. The advantage of the Speedy Stitcher and this HFT copy is you can use standard 135x17 industrial sewing machine needles. They can be bought with leather points, textile points for canvas etc. for only $1 ea in single quantities shipped on eBay.
The Tandy sewing awl uses a less common 2.5mm(very large) needle shank that is harder to obtain. You can use 793 size industrial sewing machine needles but they are less common and slightly more expensive. Not available in singles. Tandy gouges on replacement needles.
So the HFT awl isn't really BIFL like a Speedy Stitcher. But it works and it's cheap. I think my friend will like using it.