Optical waist-level viewfinders for Ricoh GR cameras
You can now buy optical waist-level viewfinders for Ricoh GR cameras on Ebay and Aliexpress. The viewfinders have different frame lines (28mm/35mm/40mm/50mm), so make sure you pick the correct version (two different models are available).
More Ricoh GR accessories can be found here.
Additional pictures:
