

Successful yashica D mirror replacement, thank you @Impolioid!
Can't comment with images, but this a reply to @Impolioid 's post about DIY'ing a TLR mirror using an old polaroid: https://www.reddit.com/r/vintagecameras/comments/1negiuz/comment/ojkw48o/
Found an old Polaroid on ebay for £1.13, sliced the mirror down with a glass cutter and it seems to have worked great!