A couple years back, I acquired the USMC MEF set, which I largely consider my ultimate grail. I decided to keep it MIB until my assembling skills got up to snuff, and I think I’ve finally reached that point - however, I’m still a little hesitant to crack him open, for two main reasons:
Age - This particular set is ~12 years old at this point, and while it appears that its previous owner stored it responsibly, I can only confidently vouch for the two years I’ve had it in my possession. I understand that, over time, fabrics fray, adhesives dry up and deteriorate, and paints fade, with poor storage conditions hastening the onset of these issues. I’ve gotten burned on this a few times with some older sets from lower-end brands (e.g. 21st Century Toys), but I’m hoping that the HT figures have held up somewhat better. My biggest fear is that I’ll open this guy up all excitedly, just have some of the smaller accessories fall apart in my hands due to age. Which brings me to my next point…
Cost of replacement - I usually don’t like to use the term “rare” when it comes to mass-produced action figures, but the reality is that I seldom come across extra parts (aside from a few regular listings from far-east sellers) or other MIB samples of this set on eBay. So, if a part on own my set decides to crap the bed (either due to age or my own incompetence), I would have very limited options in terms of replacing it outright.
I guess ultimately what I’m asking is, how well do the HT military figures hold up in the box under presumably optimal storage conditions? Is it almost a lost cause to crack the set open at this point?
My opinion after having gone through many many boxed figures of various ages and seeing the common problems is you are worse off leaving them boxed. Keeping them in a sealed package means when the various plasticizers used in the plastic production and PVC products like heads off-gas that ends up condensing back over the item causing that oily mess you see. The other problem is the plasticizers will leech out over time when they are in contact with other packaging materials. When you see oily film on head sculpts, shiny spots on the paint, or paint turning to mush this is your cause.
It’s less of a problem with Hot Toys, but the adhesive that one of the major OEM’s uses tends to turn into a sloppy goo over time. If you catch it early enough you can clean it off, but if it deteriorates too far it will permanently stain any fabric. Even when you store something in a climate controlled environment they are going to degrade faster when kept boxed, it is just a consequence of the materials that are used. As long as things are kept out of direct sunlight, exposed to open air is better.
For the Hot Toys military products I’ve gone through quite a few of those and they have held up better than anything from Soldier Story or DAM. Just mind the smaller plastic bits as the adhesive tends to weaken over time and some of the more intricate parts can become a bit more brittle as the plasticizers fail over time.
If you’re a totally purist collector, leave it in the box. But if you have any kitbashing interest or derive any amount of enjoyment from 1/6 figure assembly I’d say there’s no reason at all to leave it in there.