I got my pup from Tom last April. It is everything I expected in a quality firearm but I felt it needed a magazine extension for a better grip.
I could not find any (IDM included). So I had some made up and they fit the bill for me.
So when I came across this post and saw the activity and time its been taking (same thing happened to me) I would like to offer any help or advice I can offer.
After trying several prototypes for fit and finish I finally was able to get the right combination.
If for any reason you can't get these completed in reasonable time or cost I could contact my supplier and see if they are interested in making a batch.
Here are some pictures of my extensions.