Convert old websites to Rapidweaver: which theme and method?

I have very old web sites, made around 10/15 years ago, now unreadable with tablets and phones, but very bad also if opened with a desktop pc.
I own Rapidweaver6 and many Themes, so I would like to convert them in the most readable way, because they are mostly text based. Could you suggest me the best themes and the easiest method to convert without redo from scratch?

My old sites are:

I’m not sure how much difference themes will make. That’s up to you. Certainly something that is responsive (there are a lot of those). I really like Volcano by ThemeFlood, but there’s tons of other choices. Plus there are the newer semi-build-it-from-scratch themes: Foundry, Foundation, and more. These might be a good choice for you. I love Foundry.

… however you are heavily text-based. I would suggest the best thing you can do is convert to using Markdown. I believe there are a few web-based tools for converting HTML pages to markdown. Markdown is a very simplified HTML language. It will make re-doing your pages a lot easier. It also means you can easily store and edit all your text in apps such as Byword, iA Writer, Ulysses, and Scrivener.

Thank you for the Markdown suggestion. I never used it but I took a look and it seems, really, a kind of easy HTML. I will also search for some HTML > Markdown converter. Then the best Theme will be a very simple one. I have some Weaverthemes: Cellular, Autonomy, Prospect, Jovial and Shift. I have also some Nick Cates’ but they are too graphic, not very suitable for text pages.
I purchased also Foundation full suite, but I found it too difficult.

Use this theme:

I’ve used this in the past:

For a site that’s basically text and images, I’d take a look at the lovely and free Basic Blue.

You may really want to take advantage of headers (H1 through H6) when using Markdown with lots of text. This has many advantages for the user (much clearer structure, etc.). It also allows you to take advantage of Will Woodgate’s Jump stack. I don’t use it to “jump” from page to page, but I do use it to auto-create a table of contents for a long page. That table of contents can be placed in various locations, and styled as you want. (I put my table of contents in a side area via the Glider stack.) More here:

I have to agree with Mathew that Themeflood have some of the more elegant themes for text based sites. Navigation will be a consideration. If you keep the navigation simple, you could build the site using Will’s blank theme and build it up with stacks in a similar fashion to the frameworks such as Foundry, Foundation, and UIKIT.