I think your H78 is fine. Don’t wear it too much and keep it away from sunlight, take great care of it, and it should last you a lifetime.
That’s why it’s great to be mainly a Jason fan. Those hocks don’t really rot like latex does. I wear my Crash hocks all the time.
I don’t understand why Myers mask makers don’t use urethane or a different rubber that doesn’t rot(not bashing anyone atall,I use it myself for some projects).it’s a very important part of this hobby, especially if you intend on investing alot of money on masks or just one. latex is a natural material with some additives.
It’s basically a tree sap. Most of the time,the more additives that are put into the latex(fillers to hold shape better,to produce more latex and save product/cash,what most mass produced companies do)
So if you see what Nik used to use,I’m sure it had additives,hence the strange color,not sure if he tinted the color to match the original DP Kirk claytex or not (latex with Clay as a filler) but it has more fillers then RD-407 latex,which makes the latex rot faster.
My suggestion,any latex masks you own,use silicone oil spray/armour all on the inside/outside every few years. This will keep the moisture into your latex,latex can be like a sponge and dry out, remember it’s a natural material,just like an unfinished piece of wood will dry out in the sun and disentegrate over time,latex will do the same. And latex with lots of fillers can go from cracking, to getting sticky and melting/drooping, etc. All latex will eventually rot if not taken care of.
Another strong suggestion is ,to foam fill your masks solid,if you don’t wear them and only use them for display. It’s can be a $100+ ,but definitely worth it.(still use silicone oil)
I wish some people would invest in using different rubbers( yes LOL immature humor), regardless that latex is cheaper and has that latex smell everyone loves,it works great. But if you’re paying 500+ for a latex mask,you better be taking AMAZING care of it, especially depending what type of latex was used. If you plan on lots of cosplays and can’t find anything but latex,I’d buy two masks because one with long term wear use,will eventually rot,even if it takes 50 years.
Some of this may sound opinionated,but tried to be very straight forward with the info I’ve learned over the years and hope it helps someone out.
Great stuff brother! For me, I think that any latex mask can last a lifetime if given the proper care, the latex quality is great, and that stored in a very safe and cool space with ideal environment.
I moved all my masks into the closet, and they are all inside a display case! 
Don’t wanna chance adding any chemicals or things on my masks and turns out it damaged the paint or the latex.
I just keep em stuffed and displayed. Never wear my masks ever, and always in a cool and out of sunlight spot.
But those are great suggestions for mask care!
Been doing that since I got it. I mean it is a decade old but the mask is great. Also about the NAG soft and stretchy latex, yes it is soft and stretchy but it comes with a price. Sometimes the pulls have defects/surface flaws or areas that have thinner latex that make it so if you barely push your finger with a little pressure, it’ll make a hole. That’s how my H78 is, has a really thin part of latex so with NAG masks you need to be careful. I have no idea how many owners have owned the H78 I have or if they worn it a lot, hopefully not but it does drop and sag a lot without being stuffed, that might be because of the thin pull the mask is or because of it slowly losing it’s shape.
Great display! They’ll be safe in there away from dust and sunlight,etc.
Btw you have 4 KH ultimates? Lucky man! I wanna snag one for myself one day of the opportunity comes up,again awesome setup man,they’ll be fine if you keep doing that.
Thanks brother!
Go to the Ken Hertlein Ultimate Thread and see if any owners are considering selling
Your in good hands , H78 is one of the best old school Myers mask!
Very insightful. So glad you shared that with us.
Unlike the original hock that melted away in the sun 
Hey, glad I could help
Well yeah…even plastic left in the blistering summer heat and humidity will hurt just about anything. The sun…heat…main enemy of many things. Wearing a hockey mask however won’t hurt it. Just saying, wayyyy more easy to take care of and have fun with than latex and still not have the same issues like latex can have. That’s my point.
He’s being sarcastic, we both are