Re: Newly acquired Iver Johnson?
I think you mean should you shoot it with smokeless powder ammunition. The answer is usually no, but if the gun is in good shape, you could probably fire a few shots without damaging it. But certainly not more than that.
The "model" number you cite is the serial number; it may have a letter ahead of it, but to see the complete serial number and date the gun the grips will have to be taken off. Be careful in doing so; if they are real pearl (and they probably are if they are as old as the gun) they will be brittle.
Any assessment of value will require good pictures, both sides and any special markings.