That is neat.  I bought my first kit the "Lucky 7" in 1965.  I did all the projects and then put it away because I could not aford to buy any more projects. I was 17. I walk a lot of ditches to pick up pop bottle to get the money.  Now 43 years later, I dug out the tools and have started doing leahter work again.  I am busy making items for my two grand daughters they are 2 years old.  I had kept everything like your grandfather including the little blue credit slips that you got if you over paid.  I have one for 13 cents and for 22 cents. I even have the catalogs from then.  Enjoy your tools and have many happy hours using them. 
Rich