I'm no expert, but I'll get the conversation going
Bill Houghton, Sebastopol, CA, gettin' soggy
>Angelo - I've got no experience with these, just observations of them in pictures and stores, but I think the following will be true and maybe even useful; and sometimes a thread needs some idiot blithering away first to get jump-started, and I'm eminently qualified for the job, so I'll volunteer.
It doesn't look like a Lion, but a similar design by another maker (unless it's an earlier model of the Lion company). You should be able to find a maker's name on it somewhere. In the heyday of hand tools, there were dozens of companies making copies of tools that we now know from the sole surviving maker. For instance, I've got a miter box that looks like the low-end model of a Millers-Falls Langdon box, by a company called Marsh-Ayers; fine box, but the company's long since gone out of business or moved on to other things.
But I digress. Back to your question.
There should be a handle at the center of the back that allows you to move the blade carriage - the part in the middle with the blades - back and forth. Depending on the design and your metal fabrication skills, you might be able to make one if it's missing - or not.
Are there two blades? There appear to be screw holes missing screws on the right, but I can't tell if that's because the blade is missing, or just screws gone. If the former, that would reduce the value (especially if it's not a Lion trimmer but some dinosaur brand - you might not be able to get a replacement blade easily in that case); if the latter, replacing the screws should be simple if the threads in the holes aren't stripped.
Look very very carefully all over for cracks - I bought a router plane this last summer and didn't notice the hairline crack that ran completely through the casting until it got home (fortunately I'm just out $5, and can probably use it for parts). See if anything wiggles. You want it in bright light for this (my mistake last summer was deciding in the barn to buy the router plane).
Make sure that the blade carriage moves freely, or, if it doesn't, try to determine if the problem appears to be grit and lack of lubrication, or some deeper problem. Not always easy to tell in the field - I've had things I swore were broken move like tango dancers once I cleaned out the mouse droppings and rust and lubricated them. Still, if it's stiff in movement but appears to be sound, you can make skeptical noises while moving it back and forth.