They will have it for sure - it's one of the staple items for a hobby shop like balsa wood and plastic glue... 
Mike you just made 30 year old memories flood back - I used to run the radio control section of the largest hobby shop in town (used to fly those things back in the day when there were no computers in the radios to save you, no gyros etc). I can still clearly see the corner that held the balsa and right next to it - you guessed it - the tubes of piano wire!
I started my electronics apprenticeship when I was 16YO at a Brisbane firm PSA (Proportional Systems Australia) and Jim (the owner/engineer) taught me so many things that I still use on a daily basis today!!!
We designed and manufactured radio control systems for modellers and some Government departments. We made EVERYTHING from the packing box, the metal cases, printed circuit boards - the LOT!! This was back in the day when printed circuit boards were state of the art...
One of my jobs when I turned 17 and got my drivers licence was to go to the flying field at Keperra (Brisbane) and test fly new radio gear, through the week, in work time while nobody else was around - my mates hated me - hahahaha
