Untapped scrapbook resource - please come forward

I'll post about my lovely weekend later (probably today) - never fear!

I've got a project coming up that I'd like to get a jump on this weekend. After getting in over my head and THEN asking for help with my cake decorating experience, I thought I'd try to learn stuff before I just jumped into this one. And a friend at work told me later that she could have helped with the cake too. I had no idea she knew about that stuff! When would it come up?

Anyway. I'm refurbishing a scrapbook! I've got an old scrapbook from the 1940s with letters, pictures, and government documents. The pages are crumbling and falling apart and so is the cover. The letters are written front and back and some are therefore mounted with just one strip glued to the crumbling paper so you can flip them over and read them. I'd like to store those in some super-duper plastic sleeve so you can read the front and back more easily. The pictures can probably be mounted on regular scrapbook paper.

I have tried scrapbooking in the past and have realized that for my family photos, it is not my thing. Photo albums are all I'm going to actually accomplish for those. I simply want to refurbish this pre-existing scrapbook in the same format that it is currently in.

My first steps will be to remove all the pieces from the old scrapbook. Second step is to scan them into my computer. Keeping them in order is a priority, of course. Third step will be to mount them in some really safe way where we can read every square inch of the letters home from the war.

So! Who out there knows about archival scrapbooking? And once I get my letters mounted in these kind of sleeves, how do you mount them on these kind of pages? Or how do you otherwise attach them into the scrapbook? Does anyone have any advice about how best to remove the letters from the crumbling scrapbook pages? (They may just pop off with a tiny bit of force, but I haven't tried yet.)

Also, I'd like to keep this project under $150 total.

For some reason, I think Aunt Jennifer might be a resource on this, but maybe not.