I'd say you can fix anything with enough patience. I have a Mark VII Battle Damaged one that the switch came loose inside the head... I was not happy and I wasn't thrilled about taking the head apart, but I did... here's the pics of the parts...
Ultimately I found the seams where the head was glued. I worked them apart VERY carefully and VERY SLOWLY (we're talking applying pressure carefully over a period of 2 hours, I had the TV on some shows I watch, so I didn't mind doing it very slowly). It wasn't fun, but I got it all apart. I then tried using some superglue to glue the switch back in, and the switch melted from the fumes. So I had to get a replacement switch - found the exact same switch on eBay (here's a link to some like what I got, I got a 5-pack, you can look around for smaller quantity -
20x Black Mini Size SPDT Slide Switch on Off PCB DIY | eBay )
Those finally came, and I discovered don't even try gluing, no matter how little glue you put or how careful you are, it will ruin the switches. So I finally soldered a fresh one on in place of the old switch, and used some two-part epoxy putty around the switch, careful to not fill in where the LED illuminates to light the eyes, and then put the head back together (you can glue the head back carefully, that won't hurt the switch). Now I'm happy to report it's back together and fully functional like new, and that switch has nowhere to slide to any more, it's staying put in that hardened epoxy-putty.
So I would say you could definitely fix any of the Iron Man parts, but be prepared to spend some time doing it, it's not fun but it's definitely do-able.
Kind Regards,
Ken