Most of the century homes I have been in with old pine floors have gaps here and there due to wood shrinkage. So if you were trying to replicate that, you did. Throw in a few creaks and you are right there. Seriously, do you have a lot of gaps, and if so, how big? Pictures would also help. Without seeing them, I normally wouldn't recommend filling them. It usually doesn't blend in well and a lot of times works loose due to seasonal wood movement. Also, what general area are you located?