G'day folks,
Not a 'dedicated' manual, but the earlier editions of the Gregory's 'Small Engines' manual series do cover the Kirby 2-strokes. The current #426 does not.
Like this one - it's the 1982 version of Gregory's #199.
There's a rundown [from the Victa coverage standpoint] of the various editions in this thread:
https://www.outdoorking-forum.com.au/forum/ubbthreads.php/topics/81688/