[Arran]

Actually there are three ways to cut veneer, plain cut, quarter cut, and a third called rotary cut, rotary cut is usually what you will find in construction grade plywood, if in doubt I would just look on some websites that sell veneer for a veneer that matches. For buying I would try ebay, search under French Walnut veneer and see what they have that is close. Other then that you would have to order from a specialty outfit like Constantines. In my opinion I think that this veneer could probably be repaired, if you had some scrap material laying around to make patches with, there is a bit of trick to it to have them blend in though.
Regards
Arran