No, The JC Higgins model 29 is just like the model 31 without a sling. the difference between the model 30 and model 31 is the bolt is on the left on the model 30 and on the right on the models 31 and 29. Models 30 and 31 both had a retractable sling.
The J.C. Higgins Model 43 was manufactured by Marlin Firearms. It is the same as the marlin Model 83 Blackhawk_45 The J.C. Higgins Model 43 was manufactured by Marlin Firearms. It is the same as the marlin Model 83 Blackhawk_45
Is it a shotgun or rifle? Caliber/gauge? Not a model number I have seen. They are usaully marked something like J.C. Higgins Model 20, 101.1, 583.13, 583.2078 etc.. Without more info, no way to know who made it. Could be be Sako, Savage, Marlin, High Standard, Stevens
The JC Higgins Model 45 was made by Marlin and is basically the same gun as the Model 336. Manuals are availabe from Marlin Firearms. The JC Higgins Model 66 was made by High Standard and is out of production. I have a manual scanned, and can email it to you. email@example.com