Hinge question

I’ve been saving up my questions——

I’m working on a box for my cat who will not be with me much longer (21 years is a long time). Anyway – I’m limited to what I can make because of my orthopedic issues. So to say it’s not going to be the best box I’ve ever made is an understatement, but it’s the thought that counts right?? right???

Long and short it’s just butt joints screwed together and some trim I had around. Everything has been done left handed, which has been a chore. I didn’t know you lefties had to work so hard to get anything done.

But now I’m onto the lid. I’m going to use general purpose butt hinges. I’m going to chalk this next sentence up to, it must have been the medication….. but I’ve managed to mortise in the recesses in the box itself. Yes, left handed, it took about three hours on each recess and a couple of band aides to boot. Not sure why I put myself through that torment, but I did. I’m thinking I’ll never get this lucky again, but the recesses are not too bad, I’m only a tiny bit too deep, a smidge too much. So now, even though this box is going to go into the ground and no one will know the difference but me, I feel like I need to do the recesses for the lid. I’m thinking that I’m punishing myself for some past life transgression. But it is what it is.

So here’s the question, what’s the easiest way to measure the recess for the lid so that you know it’s going to sit evenly across the width of the box? Do you sit and measure twice, then measure again, do you rig up some way to hold the lid upright while you mark it, do you call GaryK to come do it for you? What’s your method?

-- Betsy - GO BUCKS!