couple of thoughts.
considering the two crank oil channels were not drilled, there is a non zero chance that if you did a DIY drill out or water jet the crank will not be balanced...no? I've never done the machining myself, but it would appear that removing that much material in two directions on the same "plane" would necessitate some kind of crank balancing work afterwards, no? just intuitively, that looks like at least about 2 ounces of metal that would be removed if you did the drill out. two ounces is probably going to cause problems with bearing at 3600 rpm..I would imagine. I dunno...not a machinist...but it would seem there is more to this job than just drilling it out.
also this: there does appear to be some crank wear likely due to lack of lubrication (not lube channels).that dull gray streak looks like a red flag to me...I'm not aware of how this crank is built or how one would relap even if that is possible...