David Weaver
..to address the chisels at are out there from I&H sorby.

you've had one of these

This is a yes or no question:
* the chisel (two of them) has grind marks that go end to end and the marks on the small bevel match the rest of the chisel in terms of fineness, and there is no fine edge on the chisel and no sign of damage (it's not blunted off)
* there is no sign of honing on the bottom of the chisel, the mill marks at the bolster are identical from end to end (very finely finished, but obviously by a wheel as all of the marks progress parallel to the direction of the chisel
* the curvature on the tops of the chisels have the same mill marks on them, no evidence of being stoned or ground with something else
* tooltique has chisels that look identical (you've dismissed them because the guy does minimal restoration)
* bode's listings of IH sorby have this rounded top unless they're short (those still have a rounded top, but it's sloppily refreshed in some cases)
* all of the chisels shown pictured anywhere with this roundover have a similar look

This chisel was modified by later users, including some who never used the chisels or honed any other part, and all of them match (all of the different users made an identical looking roundover) - yes or no.

Now, let's do another survey of likelihood -if this was done to the IH sorby chisels, I should be able to find neatly redone marples chisels and a sample of all of them from a similar time frame should show that most of the marples chisels that are full length should be rounded over.

There's no unknown variable that would make them different.

IH sorby (you have to parse the I sorby and R sorby out, different maker):
https://www.google.com/search?q=IH+sorby+pigsticker&tbm=isch&ved=2ahUKEwjQvPDu5tTqAhUO0awKHcEUBmMQ2-cCegQIABAA&oq=IH+sorby+pigsticker&gs_lcp=CgNpbWcQAzIECCMQJ1DzDljNFGDJFWgAcAB4AIABZYgB4gaSAQM4LjKYAQCgAQGqAQtnd3Mtd2l6LWltZ8ABAQ&sclient=img&ei=y94RX5CrPI6iswXBqZiYBg&bih=969&biw=1920#imgrc=Jok-GiD0HEElJM

Marples:
https://www.google.com/search?q=marples+pigsticker&sxsrf=ALeKk00MkBQJmPTkhgRJY9nDRoNzkFrWrQ:1595006620298&source=lnms&tbm=isch&sa=X&ved=2ahUKEwjDnpHY5tTqAhWFB80KHfGgD_oQ_AUoAnoECA0QBA&biw=1920&bih=969#imgrc=GNGhjsA0n5fn_M