Swaim Die-Cut Vs Imperforate Rs235

I came across a Swaim private die revenue which has me wondering about what "die-cut" means for that issue. The die-cuts that I've seen, the top and bottom edges curve-in heading towards each end (top stamp in the photo). The bottom stamp is obviously not cut the same. Is this an imperforate which was trimmed down, or does "die-cut" for this issue mean it was cut by hand and there is some (a lot of) variation?

These are both die cut, which is a misnomer because they are actually cut by hand, not true die cuts. The imperforate Swaims are rectangles.

Thanks. That makes sense. Even the "normal" die cuts seem to have some variation that I would not expect from machining.

I guess the person cutting the bottom one had a bit too much Swaim's Stomachic Elixir before coming into work.

If that were not true, then one would have to examine the margins under high power to try to determine them. This makes it a lot easier.