Hoffritz Slant, in Original Leather Case. Date?

This arrived today, blackened all over but not from a silver tarnish... 

I was struggling, then noticed a peeling lacquer all over, pretty much... and so I took a risk: nail varnish remover (wife’s, ahem). 

I worked slowly, removing the sludge, and despaired at one point but I persevered. 

And just LOOK at the results! A bit of a polish, voila! 

There is some dispute re the date of these leather-cased variations, but I think it’s pretty rare. Some say 60s; some say 70s (?)

Before: