I think it was silly to leave them in the shed in the first place, and with expensive bikes, thats the kind of thing you keep in a secured garage or in your house.
Well to me (sorry if this is harsh) -
you cant rely on the police, tbh they cba they too over 30mins to respond to my urgent 999 call which was appulaing to say the least!
As i said before you need to make your stilts known in your area you need to make it very hard for whoever has them to do ANYTHING with them also put in local papers/shops etc possibly offering a small reward but dont state the amount just say a reward will be given.
I also advise you to stop posting on diferent threads trying to get sympathy about it, because at the end of the day its your fault. eg i had my bike stolen from school - my fault as i didnt lock it up i couldnt blame anyone else, and sympathy wont make it anybetter.