Two things in the area of phono collecting I personally try to resist spending big sums of money on, are needle tins, and acetate records.
Needle tins WILL deteriorate over time, simply because of what they are made of. You can take steps to slow the deterioration, but unless you store them in a vacuum, it's going to happen eventually, and there's really no way of knowing whether it will take 100 yrs, or 1 year.
I've got tins I've had for 30 yrs, and some are now unreadible while others have remained the same, yet all have been stored in the same way.
The spots in the paintwork of the Mickey tin are stains caused by the early stages of corrosion underneath the paint, and once that starts, there's no way to stop it, short of stripping the paint and treating the corrosion. The thing is, you dont know how long it'll take to get worse, so in my books it's a bit of a gamble when you're laying down what could pay for another machine or a favorite record that you can be entertained by for years. Tins are great to have and collect, but really all they do is sit there looking pretty.
Here's a link to a wonderful collection of tins, including some Noris tins. The one with the dog in place of Mickey I've seen a few of over the years, but I dont recall seeing any of the others.
http://www.flickr.com/photos/nja1/34924 ... 180540017/