Please let me be the first to welcome you to the forum
... I'm quite new here, myself.
I have a grey 'Photomicro Adapter L' available, if you can't find a beige one.
I was intending to put it on ebay, but, if you are interested, please send me a message, and we can discuss.
For info: here is one recently listed on ebay.https://www.ebay.co.uk/itm/Olympus-Microscope-Mikroskop-OM-Mount-Photomicro-Adapter-L-e-/182819192485