ok sorry but the refrence books didn't list a md 58 for some reason made by western field and i checke 3 books ,,i beleive the savage model 7 or 7s parts will work ..i had to do a search to see a pic,,refrence says made from 1930's-50's refered by some as a gill guns because of the cuts on the side of the receiver,,hope thats what you were looking for ..try gunparts corp. for parts,,try this link
http://www.e-gunparts.com/products.asp?
chrMasterModel=089Zz7&MC=..is yours a clip fed or a tube fed model? if tube fed it would be a md 6 clip fed would be a model 7 ,,i have an old parts diagram i can try to scann if ya need one
bigcurt