I wouldn't rescrap them, and I'll explain why in a minute. But what really matters is how you feel about the pages. If you love those photos but can't enjoy looking at them because of the layout quality, then maybe you should re-do them.
Both my photography and digiscrapping skills have improved so much since I began 7 years ago. But I have so many photos and memories I haven't gotten into our books at all yet; I want to spend my scrapping time on those. I don't re-scrap photos unless there's a good reason beyond not liking the LO. The few photos I've scrapped more than once have generally been for "looking back" pages--so I may have scrapped a photo of someone's 1st birthday years ago for a page about their birthday and then do it again now for a page comparing all 3 of my kids at age 1.
When I look back at my earliest albums, there are plenty of pages that would make me cringe if I compared them to my current pages. But they're well journaled and help me remember our life then, so I'm happy enough with them. It's fun to look back and see where I started from as a scrapper. My family isn't evaluating my scrapping skills, and I think the quality difference would be more noticable if I re-scrapped a few pages and mixed pages from my current skill level with my 7-year old pages.
And just for fun, here are a few of my oldest digi pages. Designers have come a long way since 2004, too!
