Heat, cold, have a way of causing some materials such as
gokins (diecast metal, in general) to Oxidate (the green grime
that forms on the surface, especially in deep crevices of ojects).
Incase anyone new to collecting diecasts and plastics (like me)
might think of Going There: Do NOT use Brasso!
That stuff will ruin your gokins with such excrutiating severity
most colosal to gokin-kind.
Would you put Noxema on a baby? Don't think so...
...your babies will hate you for it.
Smokers (I'm a smoker, too): Cigarette/Cigar/Bud smoke settles
like dust on surfaces... when ignored, leaves a horrible grime
on the object;
prolonged exposure causes discoloration... Or even worse.
Traces of THC oils in bud-smoke does a gokin/plastic really severe.
Bad for gokins and plastics.
Set up some kind of ventilation to, at the very least,
keep smoke away from your babies...
A glass case helps protect your babies from smoke and
other harmful elements.
If your budget is tight, a simple glass case is easy to build.
Young children are fascinated by the sight of "toys", and will grab to
play with your babies...
When guests come over (with children in tow), it helps to educate your
guests and their children so they understand how much your
valued babies mean to you... nothing is as painful as watching your
babies get damaged in the hands of an innocent curious child.
If you have an extra baby available (or something as Fascinating As),
offer it as a gift to the child (this will distract the child from your investments).
It's better to give away a similar extra item, than to lose Any
of your valued babies.
Thought I'd add my 2cents worth
zozo-Magengar