Hello Joe,
Thanks, I am familiar with the process, in this case I think a toothpick will probably suffice. If no one comes up with specific dimensions it will be a case of try a selection of small screws until one is found that fits, and take it from there.
The other dimensions I can approximate by enlarging the picture and scaling the sizes from a known dimension, such as the trigger pin which is 0.10" in dia. It may not be precise, but a blind man on a galloping horse might overlook it.
I tried your contact numbers several times but got no reply, the time differences don't help either.
Harry