The image would have made this puzzle very challenging if it weren’t for the pattern of the pieces. All the pieces alternated between one of two shapes - knobs on the top and bottom with holes on the sides; and holes on the top and bottom with knobs on the side.
It’s kinda hard to see when it’s assembled, but most of the pieces looked the same when they didn’t have surrounding pieces to build the image.
Aside from that, the pieces were small and flimsy.
Nice picture!
On edit: We just trashed a used Sure-Lox we bought at a thrift shop, in addition to missing pieces far to many were mutilated, with the small thin section near the hole torn off. I can enjoy a puzzle with a few couple pieces but mutilated pieces that do not stay together is too frustrating. We did new Sure-Lox and they stayed together but fragile.!