As far as checking, if oil wasn't replaced on a regular basis, often times you will see sludge in the engine. If you remove the oil fill cap, look down into the valve cover to see if it appears clean.
Also, if you are replacing the timing chain, the timing chain cover will indicate a lack of maintenance the same as through the valve cover.
As far as abuse goes, that is a tough one. You usually won't see visual evidence. You would need to do things such as check engine compression. However, if there are aftermarket performance parts on the engine, that could indicate it was run hard. So, I guess you indirectly could see things.
Let me know what I can do to help.
Joe
Saturday, December 24th, 2022 AT 12:41 PM