I am looking for some in-line gripper lead molds. Does anyone know of any online shops that carry them?

Try looking on eBay. Plenty of Inline gripper moulds on there.

In reply to Post #1
https://jbmoulds.co.uk/

Not cheap but the finished lead is much better than when using the cheaper molds. These are cnc machined so the two halfs fit together perfectly, the cheaper stuff isn't so you get a lot of seepage around the edges which reqiures filing off.