wow thanks for all the addition information everyone.
So the last time i tried to let them play, I set up a fairly small fenced in area in my room. I let them both run around in it by themselves so they could get used to the area (about 15-20 minutes each alone). Then I placed neo in first (since he seems to be more aggresive, he still nips at me!) and i stepped in with Gus. Before I could even put Gus down Neo ran up and bit Gus on the nose. I immediated took Gus out, put Neo back in his cage and then let Gus play (to make sure he was ok). In the past after a scuffle Gus has acted like a hurt child; whiney and mopey. (past fights were more rough playing, a bit of fur coming off though). This time Gus was acting fine so I assumed everything was ok. There was no blood and Gus was in good spirits running around playing cheerfully. about 2 days later I noticed a little scar on poor Gus's nose. This worries me a little. It seems that the boys just want to fight and not really be friends. I have them both in my room but with cages about 3 feet apart. I am currently still switching them between cages and toys but they are not allowed to play. Neo isn't really tame yet anyways. Gus used to nip at me alot (especially though the cage) but now Gus is very sweet and rarely nips at all (he is such a good boy) Gus used to throw temper tantrums in his cage but now he patiently waits and is pretty affectionate.
Neo is a bit more aggressive. He isn't too interested in me and I haven't really ever seen him popcorn (which worries me) he seems happy but no popcorns. The other day he sat on my knee for about 2 minutes while my girlfriend was tapping on some cardboard and scratched him a little. He is slowly getting more affectionate but still tries to bypass my hands on his way out and isn't as affectionate or trusting. I figure that i'll have a better chance of having Gus and Neo friends when Neo trusts me a bit more, although I do worry that they are getting older.
I will never use the smoosh method in fear that Gus will get hurt again. I like the stuffed animal idea but like i said im taking it extra slow this time. the boys seem to be super territorial when it comes to their cages. If gus goes anywhere near neos cage neo will get on his hind legs and bite and the bars and vice versa. I am still hopeful that one day they will learn to get along but i have accepted that the possibility of this is low. I don't think either of them get that jealous as long as they both get turns to play. Gus seems much smarter to me. He is much more agile and his balance and jumping ability is nothing short of impressive. Neo is just a bit more rough, but his balance and coordination is inferrior to Gus. I'm convinced Gus is a runt because he is pretty small and smaller than Neo for sure.
I will def continue to swap cages, toys and dust baths and this stuffed animal idea sounds great. My priority right now is to win Neo over though and just make sure my boys are happy
Hopefully someday they will be friends.
Right now Gus has been randomly humping things though which is new. Honestly it is a bit amusing when i see him run up to one of my blankets and hump it. Neo mainly seems interested in running around and chewing on things.