Great to see you again, Will.
Aha.....yippee! Another grown up who has fallen for the subtle charms of the sweet little HW30S!
Those sights are not standard or available from HW. Gary and others will be able to better advise likely sources and the model number. I think most people source them from that on-line auction site. Many threads on here in the past and IJ has often posted useful information on them.
Think I'll have to have me one too at some point.