When I was younger and growing up in the 60's, you could buy model kits at the 5 & dime
( Woolworth's, Steadmans, Kredskis ) and at the grocery store that my mother worked at which was Loblaws. You could also get them at other grocery stores as well. The big department stores like Eaton's and Simpsons and Sears carried them in the toy dept. But my favorite place to buy models was my local hobby shop that was run by a old couple who were friends of my dad.