Thanks for the offer Mark...but I'm on nights at the moment...so lots of daytime zzz's to be grabbed.
I might take you up on the offer next week though (although that depends on how easily I can get the spares at this time of year).
And a thought to ponder...why is there always one mystery bruise after you've had an off? I have no idea what walloped my left calf...but it was harder (or more pointy) than the road