My old (30+years) Bosch two speed hammer drill shed a tooth off a cog a few days ago after one of those oversize blacksmith style drill bits snarled up and stalled the drill in a nanosecond :-( A few attempts at buying spares online looked promising initially but failed do the the part being obsolete. 
So I need to replace it. It was a great drill without one of those stupidly unreliable trigger operated speed controllers and served me well for 3 decades. I'd like to try and replace it with as near to ''like for like'' as possible. Suggestions and recommendations please for a new drill that's built to last and will stand up to serious work on occasion like concrete drilling and 1" blacksmith drill bits.
Thanks Julian. I don't suppose anyone has the capability to make a new gear to a pattern for not too much cash?