Ok, well you threw me when you mentioned about Raleigh, as I didn't think the common keyed style bolt was especially linked to them. Anyway- I've several of the non keyed bolts, although most of them are pretty long for your 19mm length limit. But would this measurement refer to the clamping size or just the length of the bolt itself? I understand that the clamping size means the measurement between the inner edge of the two heads of the bolt's head and the head of the piece it connects to. If you mean clamping size, then I have maybe two that are small enough for this.