Thank you, that's very kind. Here's a link to my drive with the images - best we can manage through the glass.

https://drive.proton.me/urls/V3ZCZC4FKM#aSU4aeHCgiPF

One detail that may help: it isn't a sash worn across the body. It's a plain pale ribbon, about the width of the medal itself, hanging straight down from it on the left breast. No apron or collar is visible.

I've also asked the Museum of Freemasonry, and I'll post whatever they say here.