I've now found the text on archive.org searching under upapurana
Harry Spier

On Sun, Aug 9, 2020 at 9:50 PM Harry Spier <vasishtha.spier@gmail.com> wrote:
Dear list members,

Does anyone have a pdf of the Sāmbapurāṇam.  I couldn't find anything on archive.org.

Thanks,
Harry Spier