Train goods stores in Tokyo area

Does anyone have a list of or information about what train operating companies have souvenire and merchandise stores in and around Tokyo, Chiba, Kanagawa, etc? I've looked on Keisei, Keikyu, Odakyu, and other websites but can't find any information, but I know these stores exist. I'll be visiting Japan and would like to visit as many as I can.

Thank you.

Train merchandise is commonly sold inside platform/station shops along with other ordinary things like snacks and magazines. If you ask directly to a store clerk, they'd usually know the branches with more variety or a specific store that usually have stock of specific merchandise. Some companies have museums where they'd have shops.

I'm afraid I was only able to find info in Japanese language, but here they are (These info were easily found by Googling "company name グッズ" in Japanese):
https://www.shinkeisei.co.jp/welove/goods/
http://www.otodokeikyu-sc.com/html/page2.html
http://www.otodokeikyu-sc.com/shopbrand/all_items/
http://www.odakyu-trains.com/
http://www.e-toks.co.jp/product/original
http://www.e-toks.co.jp/shopinfo
https://www.jreastmall.com/shop/w/w10/

I hope that automatic translation or your hotel personnel can assist you. Enjoy shopping!

Most train companies have their own museums, and the museums always have very well stocked gift shops. Here are most of the ones for the Tokyo area: https://whereintokyo.com/dbinx/museums.html#trains

@Umami Dearest. Wow, this is a great link about obscure museums. Now I know what to do next I am in Tokyo on a rainy weekend. thanks!
Eg the brakes museum sounds intriguing.

@LikeBike, I love the brake museum! Back when Skytree first opened, Sumida-ku had an initiative to encourage the creation of mini-museums showcasing both small industry and handicrafts in the area, and that was one result, along with the Meishi and Paper Products Museum and dozens more.