Reading online about a couple of guys that started collecting and selling classic football kits, checked them out and some of the Rangers shirts they have on there are quality. Worth a look if you collect shirts - some do seem fairly pricey though.
https://www.classicfootballshirts.co.uk/other-uk-clubs/scottish-clubs/rangers.html?p=2
https://www.classicfootballshirts.co.uk/other-uk-clubs/scottish-clubs/rangers.html?p=2