Hi PeCo, and a warm welcome back to the forum. I have made some inquiries for you...if you ring John Humphries or email him, he may be able to help you with the rings or put you in touch with someone who can. His contact details can be found here...Click... HERE
Hoping this is of help.
Please do not PM me asking for support. Please post your questions in the appropriate forums, as the replies it may receive may help all members, not just the individual member. Kindest Regards, Darryl