Doing so more reading, apparently, this was used on the sun twice during Hubble's Orbital Verification.
Glenn Schneider assembled a mosaic of the "best" images from the WF/PC "Flood Guiding Verification Test" data acquired during OV-1. This shows a rough image of the Sun at 1220 Angstroms. As Glenn noted, these are the "first, and last, images of the Sun ever to be taken with HST."
Thanks to Phil Plait (npub1ctj…de0g) for pointing me to this over on BlueSky.
http://nicmosis.as.arizona.edu:8000/UVFLOOD/HST_SUN_IMAGE.html