Thanks for the comments folks!
To those asking about the weights I'm honestly not sure, as these were designed to be pure replicas and whatever weight they came out was the weight they stayed! I can tell you that a very similar arrow based on English medieval military arrows would be around 60g, using the same shaft, same amount of fletching compound and a similar weight head.
The carvings are probably just makers marks but there's no reason why they couldn't have been runes - symbolic runes were in use waaaaaay before this period!
Archeryrob - I didn't document much of the forging as it's not something I think about much, I just get on with them. If there's anything specific I can help with or provide info on let me know and I'd be glad to help where I can!