Same SD, new RPI, lost pinouts ‐‐ is it saved somewhere?

I was having problems connecting to my REM rpi. It wasn't necessarily the source of my the connection problem, but I swapped out the rpi.

I changed the static IP map in the router for the new RPI's MAC address. So, connecting isn't an issue.

But, I've lost the pin outs that were connected to the Atlas probes, dosing pumps, and flow switches.

I'm guilty--I didn't document that anywhere. I can figure it out, but I'll have to pull stuff back out of the enclosure.

Is there a copy of what I had somewhere? Why would it change with a new RPI (same SD)?