http://www.lapua.com/en/products/rel...reloading-data
http://www.lapua.com/view_reload_tab...iteid=products
I always try to start with the powder manufacturer's data. Bullet maker's data is good too, especially for overall length. Vihta Vuori doesn't show N135 for this cartridge. They also make specific reference to their load data NOT being for older Marlin 1895s.
There is a 45-70 specific section on the Marlin owners forum. Probably worth a visit.