While made by a different company, the pruners look very much like this:
I cut a branch of mulberry that was a larger diameter than I should have. The pruners now are slightly looser than they should be. Also, the latch that keeps them closed no longer works. Because it won't close as far as it was originally designed to.
Can you tell why it won't close as far as normal? What's interfering?
"Hundreds of years from now it will not matter what my bank account was, the sort of house I lived in or the type of car I drove... But the world may be different because I did something so bafflingly crazy that it becomes a tourist destination"
Maybe. It's worth a try just to get the feel for fixing stuff. If it doesn't work or you snap the handle off, keep eyes out for another nice used pair somewhere.
Close the clippers (you said they were loose but I'm assuming they will close?) and look them from the "narrow side", ie. turn them 90d from the way your pic shows the sample clipper. You are looking to see if there is space between the blades (there should not be); hold them up to a light colored or otherwise contrasting background to see easier. If there is just little space showing, figure out which blade has been bent (hoping only one) and whether the bend is above or below the bolt hole. Place the blade into a large solidly secured vise so the beginning of the bend is just above the jaws and take a 3-4# short handled sledge and administer correction. Using a relatively heavy hammer "gently" (or somewhat less gently) gives much better control than taking a full swing with a lighter hammer. If you want to apply force at a very specific spot, cut or make some kind of punch or block from something, place the business end exactly where you want it and hit the block with the hammer.
Put it back together, not wasting time tightening too much, and see what you've done. Depending, you might have a 30-40% chance of correcting the tool. Try again until you're happy, break it in half, or give. up. <G>
Next time, squeeze hard and then rock the clippers, staying in the plane of the blades, until the wood loses its grip, then shift the clippers around the branch a little, staying in the original plane of the cut, and squeeze hard again. 3-4 repeats usually cut the branch. Or just use real loppers as gawd intended. Or a pruning saw.
Sometimes when I'm trying to do basically what Rufus has suggested, if the blade end is in the vice I take a heavy walled pipe and slide it over the handle to give myself a longer leaver arm. That may give me more control when I try the bend.