How long has/does the gun sit? My experience has been that a gun still needs attention when unused. Other experts sound chime in shortly.
I like Hoppe's for bore cleaning, Remington wipes for between cleanings, and QMaxx products for a complete tear-down. Kriegoff International (purveyors of Kriegoff shotguns) carries the QMaxx line. If the folks that sell 10K-to-start shotguns recommends, its good enough for me. A note about the QMaxx, the degreaser is really strong and leaves no protective film layer. If you use it, oil/coat immediately.
Spray it all out with brake cleaner and lube it the right way. Which means no oil or anything else in the striker channel. Somebody's been very naughty.
Mobile One or CLP. But that's because I have it laying around. And looking at the images from OP, WTF man!?!? If your gun looks like a homeless person's ears, you are doing it wrong.
M Pro-7 for regular cleaning. Hoppes Black Step 3 red oil which also smells good is meant to endure high heat AR cycles but works well on handguns also. Barnes CR-10 for barrels that have caked up carbon works wonders. It's a copper de-fouling agent so be careful with it but the barrel will look brand new
From those pictures and my own experience, it appears that too much lubricant may have been used. The gun was shot a few times and re-oiled without being cleaned and put away and forgotten about. Just my .o2cents