Just so you know right away, I'm not making a dime, Euro or peso off this.
Thanks to many previous posters, I've found a really, really nice whistle bag and I'd love to share it with you.
The bag came from Brigitte and Colin at Overton: extremely nice people to deal with both on the phone and through e-mail.
The Celtic design was added by another really nice woman, Kristen, of KAM Sew Unique whom I met at an Irish festival at the Pennsylvania/Maryland border. Due to the large size and thickness of the bag, I suggested she put the design on a separate piece of fabric, then attach that piece to the bag. (The bag is black but I lightened it for contrast.) The bag cost about 60 Euros including quick shipping to Pennsylvania from Germany and the embroidery was another $35 including UPS ground shipping. I'm certain Kristen can embroider similar pieces on a bag you may already have. She's very detail oriented.
Below are two quickie photos of the bag and the great design. For more info:
http://www.overton.co.uk
http://www.kamsewunique.com
*Note: I ordered a bag big enough for a Low C even though I don't own one yet. My Kerry Low D has plenty of room and there are several straps already on the bag that didn't show well against the grass. I had the design put on the top of the bag juuuuuuust in case I try to open it from the wrong end and dump everything out!
Joe