The Andersons at 161 and Sawmill has a good selection of fasteners and might be good first stop - since you're in Dublin. If they don't have it, as Hue said, Roush might. And if Roush doesn't have it they can probably tell you where to find it. If you don't have to have it today, McFeely's (click) has anything and everything you could ever want. edit: just re-read the OP and saw you didn't want to go online. Oops! Still, McFeely's is great and has everything. I've shopped with them, they're quick and trustworthy.