With Mulder on the way back, we have a good opportunity to more accurately rate him on the basis of his interim performances.
In terms of reach and strength he is borderline amateur. Not sure how his would be properly represented statwise, but BB 80 and Jump 89 just don't seem realistic.
Technically Kostas' is quite sound, so I would leave his GK-skills untouched. Perhaps a slight raise in kicking abilities, where's he's more composed and overall superior to Mulder.