lilolil, I loved all your posts on this, you're so right that it is a fleeting memory in what is a lifetime of memories. It's for that reason that I think it's good not to focus too much on this issue;
and it is so personal, Pink, you must only do what you want to do.
if it helps at all, I went to see my grandad when he died as we were close and he was a big part of my life, and I simply wanted to say goodbye to him. I'm glad I went. He was so obviously dead that it was a big help to me in accepting that his life was over. I mean, obviously I knew he was dead but seeing death is different; the stillness is not the same as someone who is deeply asleep and I found that surprising. he was like a stone.
I found it a really powerful thing actually seeing him, because it hit me hard about the supposedly important things of life not actually mattering at all; house, car, work, possessions, stuff we spend all our time on. When I looked at him there the things that leaped out in my mind were only about HIM, his personality, his achievements in terms of bravery and spirit, his being a nurturing dad, and his kids that he left behind him to carry on.
As you can probably tell I'm SO glad I said goodbye, and I still remember my feelings that day and use them to put life in perspective when i'm being drawn down the road of worrying about unimportant stuff.
just a personal view of course - I still think it has to come from you; if you really don't want to, don't. Your nan would want you to remember her exactly how YOU want to.