You know, Ken, a guys got to know his limitations. With all due respect, if you are asking if a gun can be converted back to 2 1/2 inch from 2 3/4, I going to guess you have much, much more to learn about guns in general, good guns and best guns.
Don't feel bad. So do I. So do most of us, if we are honest.
You are also going to have to think about what you are going to use the gun for. If the gun is mostly for fawning over, with a small bit of perfect bluebird day shooting thrown in, and the knowledge you will sell it sooner, rather then later, this isn't your gun. Lowell can tell you about that. Guns really aren't good investments and if that is the primary concern, you may need to look elsewhere.
Keep in mind, most 'chicks aren't impressed by Purdeys. So, don't buy it to impress anyone other than yourself.
HOWEVER, if a Purdey is all you have ever wanted, if you have burned for one for half a lifetime, and you are going to use it, and use it hard, for all manner of hunting, and can use the gun with the same limitations it had when it was new (low pressure ammunition EITHER 2 1/2 or 2 3/4 length, the length of the ammunition means NOTHING, the pressure level means EVERYTHING) and pay for an inspection by someone like Kirk Merrington to give it the OK for that use, it may just be the perfect Purdey to be buried with some day, a great price for a top gun with lots of life left at the end. You could use it the rest of the time you have on earth, and never really need anything else.
You have to answer questions like these before you buy the gun, not after.
Good luck whatever you decide to do.
Best,
Ted
