Storing HTML source and PDF in a record

So my intention is to store both the PDF and HTML source of a tab into one record.

I prefer to review documents in PDF format but if I store the source HTML as well, so I can extract meta data from it in the future as required.

My code below seems to work fine, with the exception of the “set source of theRecord to theHTML”.
The documentation seems to imply this should work…

source ([text] : The HTML/XML source of a record if available or the record converted to HTML if possible.

		set name of theRecord to do JavaScript ("document.getElementsByTagName('h1')[0].innerHTML") in thisTab
		set theHTML to source of thisTab
		set thePDF to PDF of thisTab
		set data of theRecord to thePDF
		set URL of theRecord to theURL
		set source of theRecord to theHTML

No matter what I do the source of theRecord is always empty. Any suggestions ?

Thanks

Frank