Identify old Bush Hog Model

[Analyte]

I looking to pickup this bush hog brand cutter, and I'm unable to pin down the specific model.

The seller called it a model 501, but I'm unable to to find anything using that information. Looking at old pictures online, it appears to more closely match a model 600 or a model 266. It's definitely looks heavy duty. It does use a slip clutch and has a stump jumper if that helps

The tag is missing so that's no help, but is anyone able to better identify this cutter? Thanks

 

[Analyte]

To help anyone else that follows, with further research online plus part numbers off the gearbox I've got it down to either a model 502 or model 600.

I'm just not finding enough to further differentiate between the 502 and 600.

 

[Analyte]

Well, after all that I ended up buying a model 600. Seller had two, and this one was in better shape. I didn't need the removable side on the cutter that appears to be a 502.

The 600 has a 6446 gearbox, rebuilt slip clutch and a new driveshaft. Very old and well built so it should be the last one I buy.