Email them scans of you paperwork and ask to speak to a supervisor. They can't NOT honor the original owner that warrenty...
First post here, I've been reading here for quite some time but figured I'd add to this here.
I've been a tech for over 35 years now and have had similar experiences with Snap On when it comes to tool box warranty.
I own a KR663, and a KR555, the hinge on the lid failed, the part attached to the box cracked and began to separate just below the hinge.
This was in 2001. The dealer than told me that there was no fix and that they won't just replace the box. They would either A) give me a new lid for me to rivet or weld on myself, B), give me $200 credit towards trading up into a new box, or C), I could empty the box and let the CS or dealer ship it back to the factory.
Not wanting to spend any more cash, I opted to let them send it back, while in the mean time I bought a cheap Craftsman box to use in its place. My box was gone for just over two weeks, when it returned, it had the new top tig welded in place, not spot welded as the original had been and the back of the box was warped. The thing wasn't welded on even close and they made no attempt to repair the paint. It would lock but you had to really push down on the lid to get the lock to turn. They had also dented one of the corners pretty bad. The dealer was even apprehensive about showing it to me.
At that point he offered to trade me for a used KR691 he had just taken in trade.
He insisted that the CS rep had sent the box back but later found out that the CS had taken the box to someone he knew to get it welded. A monkey could have done a better job.
More recently my KR1100, (which I bought new), top box had a drawer that wouldn't lock, the top drawer lock hook broke off the back of the drawer, the whole thing came loose from the drawer. Not wanting to just weld something up I showed it to my dealer. He told me there's no parts for these, there's nothing he can do. The box was sold to me with a life time guarantee. The dealer told me he'd offer me fair market value on the box towards a new box, and since they no longer make a suitable matching top for my KR1000 bottom box, I'm looking at roughly $14K minus the $1500 they will allow for the old box.
I don't care to buy a new box when I'm no more than 5 years from retirement, it just don't make sense. I bought this with the promise of it being my last box back in 1986. I like the box, and don't care to get rid of it. I really like the set up I've got, I'm used to it and where everything is in this box, it wouldn't make any sense to start over in a new box at this point.
To make a long story short, after telling the story to the Matco man here he came up with a KR661 bottom box for cheap from which I robbed a lock hook to be welded onto my KR1100's top drawer. I now have a slightly imperfect KR661 in my garage and my KR1100 can again be locked up at work.
No thanks to my dealer.
If I did have to buy a new box today I'm not sure what I'd do. With the cost of a SO box similar in size to mine running over $12K or more, and the cost of living being where its at now, and the fact that pay hasn't increased now in 10 years, I don't see how a guy could ever justify or pay for such a box, let alone with the prospect of having to do it again once parts for that box are no longer available.