I had a problem, here where i live it is difficult to find resin and fiberglass so, i think if i replace them with paper and wood glue, it will give me the same result?
where are you from? In the UK i find that halfords is the cheapest, but you can find everything on amazon. I'm not too sure about wood glue and paper because resin and fibreglass dry rock solid
Believe it or not, wood glue and paper do get rock hard. newspaper works best though. The glue saturates through and though.
I built this last year. The inner rim is foam board but the outer layer and crown (top) is all wood glue and newspaper. I've dropped this helmet may times. My kids play w/ it every so often. If it weren't so strong, I wouldn't let them touch it. the problem you might encounter is loss of detail. Glue/paper combo will give you plenty of strength but if you use it on the outer portion of your build, you will loose all the fine details. Hardening from the inside.........go for it.
If you are pep-ing it, you will still need to do something about the outer portion to smooth it out. You are still going to have to Bondo it. If you don't find it in a hardware store, most auto supply stores will carry it.