What I am actually looking for is the article or project on using 813's
as triode modulators. If that expands the editions, so be it.

I will do some searching, but I think the Radio Handbook, rather than the
Radio Amateur's Handbook, may have the article you are looking for. I know
it has an article on using 813s as triode modulators, which is rather
unusual. And, I am thinking it was further back. Will go upstairs to the
radio book library and do some searching.

73, Colin K7FM