About helmets: First of all, if you've got a foreign helmet with no Snell Foundation sticker -- show the inspectors what you have and let them decide if the helmet is good enough. Some imports (such as Suomy) may well be fine, and some will have a sticker from another rating organization. If you can -- go to inspection with some back-up documentation on your helmet. Find the org. that rated it, go to their website and print out some of (or all of) the standards the helmets must meet to get their sticker. That may be enough.
As for buying a new helmet when the old one is too old (for the sticker) -- make absolutely sure that the new one has the new sticker in it. My story is that I wanted a new helmet for Nancy a few years back. I decided on what model of what brand, then went to the Snell Foundation website to be sure the helmet was included. Sure enough -- so I went to one of the onlline helmet stores and ordered one.
Well- what I got was one of the OLD helmets with the OLD sticker. The new ones were in stock -- but the store said they wanted to clear old inventory first. They would not give me return privileges (old for new). So -- now I mention that I will accept only a helmet with the new sticker inside. I suggest that you consider doing something along those lines if you're buying a helmet from a vendor that doesn't have a real store for you to visit -- so you could inspect the helmet.