I found this and the postage with Royal Mail is low. However either the photo of the filter is wrong or the filter is too light. W47 is very dark with only 3% transmission.
https://www.firstlightoptics.com/vis...et-filter.html
Also found
https://optcorp.com/products/tpo-vio...ilter-case-f47
Not sure of postage. You’ll have to fill in your details. If the postage is more than the filter just reverse the prices. I.e. a $40 filter with $12 postage. Sounds better that way.
Check with Telescope and Astronomy in South Aus. I bought some filters off the guy a couple of years ago off a Christmas clearance mailing list he had. They were all made in Japan Meade models. He may have some left.