Thanks for the confirmation. Ideally it'll need as little modification as possible, so I'm hoping there'll be a Briggs built to an almost-identical setup as the Honda. Eg my Honda engine has a choke operated by sliding the throttle to the top, whereas my Briggs has a separate choke lever and cable; I'm guessing there will be a Briggs with the same kind of system..?
I really don't have a clue what happened to the Honda engine. I'd bought a used mower to use on a temporary basis (my Briggs-engined ride-on had bent a pushrod) and it lasted only a few days. It went from running normally to seizing solid, along with a clunk of doom. I've stripped a few seized car engines in the past but never seen the kind of carnage presented by this little Honda.