Bobplates, if you are going to sell it then the question is will selling it return the investment. It's a beautiful pair and in my humble opinion highly graded material has been fetching nice returns at the auctions from what I've seen.
It's a very nice return if it gets 95 which, from the comments here and looking at the population table more closely, seems pretty likely. It's an awesome return if it gets a 98. Hope of course springs eternal!
Note that the pair came in a collection that I bought for a bunch of other material awhile back. So this was just an added bonus that I had set aside for further research.
The SCF resource is a great one and I very much appreciate all the outstanding input I have received.
So many terrific research tools from Stamp Smarter! As for the 603, working off the picture, it looks as though there might be a small gum wrinkle near the top of the left stamp. Also, might be something going on in the shortish bottom perf of the right stamp, like a tiny bend or crease. Hard to tell.