RM — Very difficult, as it is a style made by many glassworks. See, for example, Registration No. 500502 by John Walsh Walsh on 20 April 1907 (illustrated in Reynolds and in Gulliver). Same elements, but a berry between each bell, and only one berry at the lowest point of each swag. There are at least two specialist replacements websites that may be able to help rather more.
Good luck!
Bernard C.
