Reel Repair by Alan Tani

Can someone leas me in the direction of a person who can fix the antireverse knob is completely loose. The screw in the rear seems to be tight.

Something is amiss here. Does it have the correct anti-reverse cam installed? I don't even know how you could end up with it poking out the back of the reel like that unless it was the wrong part.

Could the shaft be broken in half somewhere in the reel body?

I think pn#7803 is the culprit, Although, I'm not sure what is preventing it from coming out entirely. You're best bet is open it up and have a look inside. 

Welcome aboard Woody.
The anti-reverse cam appears to've been misplaced during reassembly, ie placed inside the frame rather than being inserted from the front.
The schematic may be of assistance:
https://www.reelschematic.com/wp-content/uploads/schematics/Shimano/Stradic/SHIMANO%20STRADIC%20ST2500MGF(2003).pdf
Let us know how you get on.
Good luck, Justin