Thanks for the extra info. I've certainly seen a flanged fir cone set as a 1+6 with underplates (2+12?), however, I don't know whether it was original or put together by a dealer.
My 1055 set was 1+6 cupped with no underplates. However, I did once buy a mixed lot of jade 1054 which came with a couple of small plates which I suspect would have fitted nicely under the bowls.