Harry sorry I didn't see your post, I really don't know a lot about the two models but will try to help you and MRA.
I don't know how easy it would be to put the trigger gaurd on the PKT but it can be done. The main two things are; Is getting a stock on the PKT, the rear of the receiver is a little different. The other thing is the PKT doesn't have sights, I don't know if a rear can be just added or if the top cover needs to be replaced.
The PKT also has a heavier barrel.
Actually my $.02 on the PKT, I'd put spade grips on it and put it on a tripod.
"Government is not the solution to our problem, government is the problem" Ronald Reagan
where would you even get a barrel for one?