Jim, here is some matches,$$$$$$$$$. I am always a sucker for a new tool. I would give it a try, if it's not majorly over priced like that land cruser mentioned elsewhere.

timberwrestler, thank you. I have not seen anything like most of those marks. As you mentioned they are simular up to, well, around IIII (4), than the V is upside down and It doesn't pick up again till 10-14 in matching the English numbers, and I am not going beyond that. I have seen them in other literature, just could't place it, but not on timbers. I will keep an eye out. The lower ones look like stick figures? In the book reprint mentioned by Gable, that had some simular marks for keeping track of what was being cut and what was saved. It's interesting that O was the waste. How do we know that, if it was cut out? The X is present on many timbers. That is something I don't do but have often thought I should pick it up. I just thought the O may represent the bore hole, I do that, at times, make silly o's where the mortice is. Most likely it has nothing to do with it. How about eveyone else. Do you but the X at the ends of the mortice? Sorry I may be wondering from the snap line topic. Tim