Yes, Frog kits are rare these days, but many were re-packaged (normally in poly bags) under the 'Novo' label, although the moulding quality wasn't as sharp in some of these.
Have a look at 'King Kit' on the 'net, they might have a limited number of each manufacturer, but they only sell what they have, as they obtain some supplies from model collectors, end of business stock etc., so it's worth checking on a regular basis.