I just picked up one of these as a project gun. it's in a bit of rough shape but I plan to rebuild it and do some black powder shooting.

Would anybody happen to know where I can find a copy of an owner manual and/or load data for this gun?

I don't have much experience shooting black powder but I have reloaded and shot a lot of smokeless powder.

Thanks in advance for any help

You don't need an owners manual; you need some basic information and instructions on how to load and shoot, and clean, BP ML firearms. Come over and I'll show you. Otherwise, there are books on it, and there is the internet.....
Make sure the locks work correctly. Do not load with it capped. Snap two caps before loading. First clean the bore of oil. Load the powder first. I know, but it happens.....
Basics; use real black powder, if you can get it. 3FG. Use a substitute if you can't get real black powder.
Use #11 caps. probably. No way to tell until you try them.
Use a patched round ball; I don't know the twist of your pistol, not the bore diameter. It matters because the balls are smaller than the bore. The patch (make them from old blue jeans) takes up the slack.
Lube the patches with spit. Or olive oil. Buy or make a bullet starter. I don't know if these come with ramrods; use only hickory or ash ones.
Use 30 grains of powder to start with, more when you get used to it. ML firearms do not have load data.
Clean with water, then oil. Never oil first.
Nothing like a ML with real black powder.

Hi thank you for the information.
I am looking forward to getting this project gun underway. It should be getting mailed to me in a day or two... I will post pics as I go on it...