Thomas Gale authorized by the Royal Society to send diploma with seal to Leeuwenhoek
According to Birch's The History of the Royal Society of London, (vol. IV p. 11), Hooke read Leeuwenhoek's letter of February 13 (N.S.) at the February 12/22, 1680 (O.S./N.S.) meeting:
A letter from Mr. Leeuwenhoeck to Mr. Hooke, translated by Mr. Aston. and dated at Delft 13 February, 1680, N. S. was read, acknowledging the receit of the last letters and books sent him, and expressing his desire to be chosen a member of the Society; and mentioning, that he was busy in making two observations, which he promised to transmit to the Society.
This letter came after Leeuwenhoek had already been elected to membership in the Society on January 29 / February 8.
Dr. Gale was called upon for the diploma directed at the meeting of January 29 to be sent to Mr. Leeuwenhoeck and it was ordered, that the Society's seal thould be affixed to it, and that a silver box should be provided for it.
At the end of Birch's record of that meeting (p. 13):
Dr. Gale produced his draught of a diploma (on right; click to enlarge) for Mr. Leeuwenhoeck.