Help cranking went from slow to nothing to aww crap

[rusty ol' 69']

I'm having some trouble with the old gal. After years of cranking over just fine, I went to crank it over the other day and it went from slow to nothing. So I charged the battery, put it back in same result. So I got a new battery, and while I was at it threw on some new cables. Same result. No clicking in the solenoid or anything to indicate anything is wrong just slow cranking to know cranking. So I take off the the starter take a look at solenoid and the contacts look pretty worn, so I throw on a new one. She fires up and then I get all excited turn it off and go back in the house to wash up and take her for a ride. I'll be damned the problems back and with a new twist!!!!! Smoke starts streaming out the bottom of the starter baaaaaaad. I figure the starters toast, but did I also encounter a small electrical fire and am I headed towards an electrical nightmare, or do ya'll think the motor just fried. Any help would be appreciated.

Thanks,
Rusty