M13A to M16A swap: Would you be worried putting this donor engine in?

I'm currently swapping my Jimny’s high-mileage M13A for an M16A out of a Suzuki Liana.Both engines from 2003, the Liana engine is supposed to have only 102,000 km (63k miles) on it, while my original M13A has done 250,000 km (155k miles). However, after pulling both valve covers, the contrast is making me second-guess things but i'm not sure if this is a problem or not.How concerned would you be about dropping this M16A in? Is this anything to be worried about?Also the knock sensor on the liana had been slightly leaking/melting did this engine maybe run hot or something or is that something that just happens? i put a picture of both knock sensors to compare. The one from the m13a is also a bit sticky and soft, is that normal?And the 3 passages on the left side of the cover, what are these for? because there is alot of crap in it in the clean cover from the m13a but surprisingly the ones from the dirty m16a are way cleaner.Thanks!

the reason for the darker stained is no regular oil changes and a old oil sitting around ie not running, happens a lot on old low mileage cars, my celica from 1990 is on 200k odd miles and the engines is super clean but I do oil changes every 5k or every year is I drive less than 5k.

after fitting it I would run the engine for like 100 miles and do another oil change just so it cleans if there is any oil gunk in it.