Sourcing down to top up a quilt

I have a 10+ year old Enlightened Equipment quilt. It's the older style Rev X 20degF model which allows you to move the down around between the baffles. It also means the down can migrate away from the areas you need it the most.
I used it in a tent on the OT at the end of last year and would have liked it a but warmer, but it was fine on the 3 Capes recently in the huts.
I have just washed and dried successfully it last week and I reckon it might benefit from being stuffed with a little extra down.
I'm happy to gird my loins and try stuffing it myself but I'm looking for any suggestions of where to buy the down. And of course any tips for first timers attempting this???
thanks
kym
I used it in a tent on the OT at the end of last year and would have liked it a but warmer, but it was fine on the 3 Capes recently in the huts.
I have just washed and dried successfully it last week and I reckon it might benefit from being stuffed with a little extra down.
I'm happy to gird my loins and try stuffing it myself but I'm looking for any suggestions of where to buy the down. And of course any tips for first timers attempting this???
thanks
kym