It’s a cool bass, I contacted the owner not too long ago and he is pretty set on that price.
I have a 78 bass that has some checking too and have no desire to refinish it. As Stephen pointed out the yellowed tint is nice and the checking adds character and a sense of history.
Also, extreme temperature changes can cause checking, that happened to an old Gibson ES335 I had (left it in a car one winter night at 14F...young and stupid!), but as Greg mentioned it may also be a characteristic of this particular finish as well under normal conditions.