Project Gutenberg – All formats, plain text and many readers.  Project Gutenberg is an attempt to provide every book out of copyright to every person on the planet.  They provide most popular formats – text, PDF, ePub, Kindle, and more. Follow the link below which takes you to the Wilson's Tales section of Project Gutenberg where there are a series of tales accessible in a formatted way.  Alternatively, as stated on the page, you can read facsimile volumes at the Internet Archive, as referenced above. They are scanned copies however, so, whilst readable, they are not high quality transcriptions.

Visit the website here.

Electric Scotland – A site for everything regarding Scotland, it’s curated from a charming ex-pat Scot several thousand miles away, and is to be recommended as a resource in itself, apart from the Wilson’s Tales material. Visit the website here.

Internet Archive
Now holds scanned versions of the 6 volume set, together with a multitude of other editions and selections. Visit the website here.

On-line versions
A free iBook of all the tales can be found here.  It’s a spiced up copy of the Gutenberg public domain texts.