I have the Speer reloading manual # 11 and it does not include data to handload .45LC shotsehells.

Would someone with the #12 or #13 manual be kind enough to reply with loading info?

I'm tempted to use the published .44Mag data as I intend to use the load in Ruger Vaquero and/or Marlin 1894, both of which can handle pretty stout loads.

Speer #13 lists data only in 38 and 44 caliber for handgun shotshell loads.
I think, if you look at a box of Speer shot capsules, you'll find the data printed on the side of the box.
At least in 38 and 44 caliber shot capsules, all the same data from the manual is on the box.