Realize the dream... convince the boss to upgrade, and celebrate by taking the old stuff to the roof and the office make bets on which one will have a bigger parts spread. It makes a great half-day party.
That would be great fun!
Update. My replacement Model 2 I bought on Amazon arrived that day before yesterday. It's hooked up and working fine. In good shape for a used one too.
Last night while watching a program where they were digitizing death masks. I nearly jumped out of my chair while pointing out a Trackball Explorer being used in the process.
I use the same trackball and I upgraded from the same Logitech Trackball Marble. I have gone through several of them. I discovered a way to get a little more life out of it by refurbishing the pic button. Find a piece of stiff plastic (the clear formed plastic on a piece of cardboard that hangs on a peg in your neighborhood store works well). Open up your trackball and find the contact point for the pick button microswitch. Cut a strip of the plastic that will fit snugly between the reinforcing gussets and bend it in a narrow, sharply formed, U shape that will hug the contact rib that pushes on the micro switch. Reassemble the mouse and you're good for another few hundred thousand clicks.
If you inspect it closely you'll see that the cylindrical surface of the microswitch button has worn a notch into the contact rib so that it cannot depress the switch fully. The piece of stiff plastic you just installed makes up for that. It can't fall out because the button will hold it in place.
As long as nothing else breaks you can repeat this process as many times as necessary.
I'm having trouble picturing this- I'd love to see a picture if you had one.
BTW, I couldn't tell from your comment which model/brand of trackball you are using.
Open up your trackball and find the contact point for the pick button microswitch. Cut a strip of the plastic that will fit snugly between the reinforcing gussets and bend it in a narrow, sharply formed, U shape that will hug the contact rib that pushes on the micro switch.
My initial reply was to the post that had embedded pictures of this mouse:
This is how I refurbished several of mine to get more mileage out of them.
Remove the PCB to access the switch contact for repair.
Notice the dent in the switch contact below. (this one is not as pronounced as I've seen)
The piece of plastic that will cover the dent in the contact.
The plastic is in place... reassemble the mouse and get back to work!