Cheers Michael, good to hear someone has had the same experience and it's do-able. How many pieces was your outer panel smashed into? I never intended on a vertical jigsaw. Did you ever consider taking out the entire panel and replacing it with one whole piece of acrylic and sealing the edges? Think it'd work just as well if sealed properly? Was it difficult to get watertight? I want to make it reasonably pretty if possible!
My panel was in three intact pieces, not smashed to bits. But it was broken out none the less.
I didn't have a good source for a sheet of acrylic that was reasonably priced, so I reused what was there.
My fear in the repair was that I'd leave a jagged edge inside that would damage the surface of the paper as it slides in and out, so I used a piece of plywood as the inner form to get the inside surface reasonably flat. The plywood was removed after repair.
The pieces didn't want to go back together "exactly" like before. So there was a bit of sanding to make them fit, and then a bit of filling in the sanded down cracks.
Acetone will dissolve the acrylic, so you can use it sparingly to soften the edges of the pieces for working. But I expect if you got carried away you could melt far more than you plan.
I think if you have a good sheet of acrylic that can be cut to fit that replacing the whole panel might be easier than the jig saw puzzle approach I used. And it would probably look better in the end.
But, again, it's supposed to be used in the dark. So who cares what it looks like if it's water tight. I'd be delighted for someone to think my pictures were beautiful. I don't care what they think about my darkroom equipment.
I suspect if you saw out the whole panel leaving a beveled edge to work with, then make a replacement panel that fits properly, gluing it together isn't going to be difficult.
Keep in mind that your replacement sheet has to be stiff enough to handle the static pressure head of the water when full, so flimsy acrylic will need a stiffener. If you're acrylic sheet is thick enough that it doesn't need stiffening, then you're good to go.