+1 on this. Clean the chicken, put the whole bird in fridge for aging. I put mine in either a big ziploc or wrap it in waxed paper to keep it from drying out in the fridge. I've heard of other tricks as well.
You got all the right replies, I say.
1. Rest in the fridge minimum 1 day. I go two days normally.
2. Rest the entire chicken, then quarter/piece AFTER the rest days.
3. Nine months is a little long for grilling, IMO. I've eaten some at the age, and they do get tough. Better using a moist...