The main upgrade is the receiver. If you look at the breach face with the barrels off, you will see two allen screws in both bottom corners. Pat Laib also did an upgrade to the fore stock. Primarily both were to prevent cracking in the wood. They are an excellent gun and many great shooters have shot winning scores with the 3200s. You need to check the bores and chokes with a bore gauge, so you know what you are getting. Many of those guns have had the chokes and bores "adjusted". Many of the top shooters that I have mentioned have moved on from the 3200s as they become undependable with a lot of wear and it is getting hard to get parts for them. There are only a hand full of places that parts can be purchased. All that being said ... if you find a beautiful safe queen Trap gun with very little use and the updates (mainly the receiver), I'd be willing to pay $1,500. If you can't confirm the bores and chokes, I wouldn't want it at any price.