With the Version 29 update came the new Retro mode which contains aspects from the Zelda 1 game. Keys and arrows can be purchased from 2 shops but which shops you can get them from is randomized each seed. I have made a map on all the Shop Locations in the game minus the Potion Shop and Big Bomb Shop as those are not randomized.
If you click the images, it will enlarge them and you can zoom in on the different spots.
1. Shop Behind Bombable Wall in Death Mountain
2. Kakariko Store
3. Lake Hylia Shop
1. Dark World Lumberjacks Shop
2. Dark World Death Mountain Shop
3. Dark World Potion Shop
4. Vanilla Arrows Shop
5, Village of Outcasts Shop
6, Dark World Lake Hylia Shop
I will be uploading the Take-Any rooms map fairly soon as well and making a combined map of everything within the next couple of days! If there's anything else you would like as a guide, let me know in the comments!