Head gasket replacement?

That's kind of a trick question your showing us the block and asking if it can be saved but there are other variables that have to be taken into account. Mainly the head, is it aluminum is there anyway it can be warped because if it overheated bad enough and either the head or block are aluminum they could crack. So first thing I do is clean the head using a razor blade and break cleaner until all debris are gone. Next using a straight edge you need to check for a warp and your going to run the straight edge along the head looking for low spots or anything that might keep it from sealing make sure to pay attention to the area between the cylinders it's very small on alot of engines and that's where you will find issues. Your block looks savable another variable is if oil and coolant were mixing in the oil pan and they were for how long. Coolant is corrosive to the material they make main and rod bearings with and if there was coolant in the oil for long enough it will destroy the bearings so if you pull the dipstick and it looks like a peanutbutter milk shake then that's a issue that needs to be looked at.

There is no way to tell from that photo. Did it overheat badly?

You already have the engine apart. Why would you even want to save a head gasket? Can't tell if this is a troll question. Since the head is removed you of course replace the head gasket, after checking other variables as above poster mentions.