DON'T DO IT.
Just bought one from a fellow in your same position. He paid $5000 for a 190E 2.3-16 "Daily Driver." Problem is to make it a "Daily Driver" would have cost him another $5000
Likely hood is that the timing chain tensioner was mis handled. These are ratcheting tensioners. When mishandled they over tighten the chain and the chain literally grinds through the tensioning rail. iF THE OIL IS SILVERY OFFER HIM $200 TO $500 OR WALK.
Follow my video bloge on what happened to this one. I have the engine out and am about ready to remove the cyl head and front cover to reveal the damage.