I don't currently have any as I'm building up my collection again after selling it off a few years ago. Here's a video I found on YouTube that shows some custom figures. Although some on it are modern you will get the idea.
https://youtu.be/BR9iRDOLYMY
As phobuckets links are nolonger available for everyone to view. I thought I'd just post some pictures of my previous collection before I sold up. I don't think I will be able to get back anywhere near this collection but I'll give it a go. Lol.
He's local so I will be able to look them over first. :) will take my loupe and a uv light. :) cheers for the info. Had never thought of trying a uv light. I imagine they probably use simular techniques when grading loose figures.