Hi and welcome. DrKev is spot on (as usual!)
go to the link DrK suggested, specifically
http://www.pacair.com/mmamps3/sites/default/files/docs/HD130_Manual.pdf
I would suggest you join the amp forum as there are a couple of real experts on there who freely provide damn good info.
I'd also suggest that you join the Facebook MM amp page.
With regard to the actual handbook, it will be difficult but not impossible to track one down.
For example right now on e bay there is a great catalogue, and if I was in the USA I would get it in an instant.
MUSICMAN TUBE AMP CATOLOG 1974 | eBay
So in conclusion, you won't get one here but you may get one via the MM amp forum, or via ebay.
Get on the forum, get yourself known - they like photos too and anything you want to say about your amp.
Once you get known and getting "your feet under the table", you'll be more likely to get a response!
Heck, I'm still trying to get my feet under the table here!