Have not seen one of those handles, at least not with a push-pull arrangement.
Not likely a Lockwood item, but I’ll look through my parts lists tonight to make sure.
The detent at the end doesn’t resemble the Chief arm, as they are meant to be lockable in any one of three positions (down, straight out, and up) and this one does not have a profile that would enable that sort of flexibility.
The throttle cable through the barrel design was also used on other motors, Evinrudes of the late 20’s among them.
Hope this helps.
best,
PM T2
He's livin' in his own private Idaho..... I hope to go out quietly in my sleep, like my grand-dad did..... and not screaming, like the passengers in his car...