Ziggy,
I don't know what to advise you. I think if you need to go so that you can have closure, then I think you should go. If not, a sympathy card is OK also.
I just had to go to a wake for my ex MIL. I did it for my MIL, I did it for me, I did it for my children, and I did it for my ex and his siblings.
I am so sorry to hear about his passing. My thoughts and prayers are with you and his family.