If the machine is running properly -
 

If the machine is running properly - adjusted, proper thread, etc. -

when looking at some stitching, can you tell the make and model of machine that made it?

Hmm. That's something I've never thought about before, I don't think I could tell, and honestly I don't think I'd care, either. I think the skill of the quilter is more instrumental than the machine in making a beautiful quilt.

If I may ask, what inspired your question?

I doubt it.

I would think the only real giveaway would be for machines that make specific novelty type stitches, that would be specific to a certain brand / model.

Nope, I couldn't. It doesn't matter what machine makes the stitches - new or old, cheap or expensive. They all make stitches. I've got an old Janome, and it sews as well as the most expensive machine. It's the quilter who determines what the quilt stitching will look like, not the machine!

I can look at things in stores and can tell what type of machine was used on it like sergers, cover stitch, ect! but not what make and model

I couldn't tell without comparison. Since I do a lot of garment construction, I like a nice looking stitch for topstitching and any visible stitching. I compared models before I bought that how the stitches looked was the deciding factor.

I doubt it too.......