High B12 is common after surgery. Mine is always over 1000. In fact, I know vets who swear they feel better if theirs is over 1000. The only time my clinic ever said anything about my high B12 level was when it went over 2000 a few years back. And even then, they just suggested I cut back a bit on my supplement. Otherwise, it's met with a shrug.
weird liver numbers are also pretty common after surgery. Rapid weight loss is hard on livers. My liver numbers didn't settle down until I was a year (or maybe more) out...but they did eventually stabilize (i.e., in the normal range).
P.S. those hemoglobin and MCHC levels are so close to normal that I wouldn't worry about them. Your doctor or surgeon will let you know if they're in issue, but I'm guessing they're probably fine.