GUNNFIRE

Good day all I am looking for some advice or maybe some reassurance, I have recently sent my 2011 e91 318i M sport off for an engine rebuild after it developed a dull knock on the over run firstly this was missed diagnosed as a dual mass flywheel issue but after having this replaced the knock persisted and I was advised that it was the bottom end. not having much spare money I shopped around and found a company that would perform an engine rebuild for £1600 (I know, too good to be true and all that) the garage carrying out the work have yesterday called me to say that on stripping down the engine they have found that the oil pump has failed and will need replacing at an additional cost of £627 and on top of that the cylinders are badly scored and need replacing/machining at another £600. I asked for some photos and received the first 3 pics below a day later which has made me question them because looking at the photos of the cylinders, the surrounding block looks different to what I expected the block to look like i.e no cooling channel around the cylinder as per the 4th pic I googled. I may just be worrying over nothing but I cant get it out of my mind so any help/advise would be greatly appreciated. many thanks