Here is a little maintenence kit I put together to keep my Echoplex running smoothly. Cleaning supplies, backup tape cartridge, etc. I found a cool foam lined case at Harbor Freight to keep it all in. You could use a small toolbox or even something like a sewing kit case, or whatever. A good place to find this kind of thing is at the thrift store or Goodwill. I've numbered the items in the picture and listed them in an explanation below.

1. Caig Rubber Cleaner: Some people think it's ok to use alcohol to clean pinch rollers. Just Say No, and use a proper rubber cleaner like Caig.
2. Isopropyl Alcohol: Use it to clean everything else. I bought a gallon from the hardware store, it's a handy thing to have around the shop. I cleaned out a travel shampoo bottle to carry it in.
3. Mini toothbrush: I got these in the dental care section of the pharmacy. They are called Proxabrush Trav-Ler, they are great for getting into tight spaces on the Plex.
4. Unwaxed dental floss: Also from the pharmacy, great for cleaning the tape guides. Make sure you get the unwaxed kind.
5. Q-tips: Get the kind used for cleaning tape decks, not the ones your mom uses to put her makeup on.
6. Tape pressure pad: Mike Battle supply's one with each new tape cartridge, keep the old ones because they can be repaired and re-used.
7. Spare tape cartridge: If you are using a tape cartridge from 30 years ago, replace it with a new one. Cartridges with modern tape in them are a must, so is a backup. Without a cartridge your Plex is just an expensive doorstop. Keep the old cartridge, it can be refilled with modern tape.
8. Spare drive belt: These last a long time and are a bitch to replace but it's good to have a spare, they are cheap.
9. Magnetometer: Got this off Ebay, it is used to tell when the heads need to be demagnetized.
10. Demagnetizer: Used to be common in Hi Fi stores, now somewhat rare but not impossible to find. I got this off Ebay too.
11. Razor blades: For splicing tape when refilling cartridges.
12. Splicing tape: These little strips with peel away backings like Band-Aids are a lot easier to use than a roll.
13. Splicing block: Another formerly common item now hard to find. You don't have to have one but it makes splicing tape a lot easier.
14. Bulk tape eraser: Show below. I got this off Ebay and put my Plex cartridges on it every now and then to do a good full blown erasure of the tape.

Great case I found at the Harbor Freight discount tool store.

Old Sixties bulk tape eraser I got off Ebay