The first mark is the crossed keys and umbraculum of Rome (technically the arms of the
sede vacante), in use 1797-1799.
The second mark is that of the Roman silversmith Giovanni Veglianti (1754-1815; master 1790). It is a branch of coral, taken from his shop-sign, which he had assumed from his his predecessor, Baldassarre Pieri (1708-1789).

Hope this helps!
Ref: Anna Bulgari Calissoni,
Maestri Argentieri, Gemmari e Orafi di Roma (Rome: Fratelli Palombi, 1987), pp. 50-51, mark #141, and p. 434, mark #1068a.