Hi Sue,
Thanks very much, this must be the Jeffrey I'm looking for. Interesting to see his father was named Richard. Jeffrey's son, Richard Bignell Lett was born 1774 in Souldern Oxfordshire. Jeffrey also had daughter Susanna born in 1787, as did Richard Bignell Lett. I wouldn't be surprised if your Susannah and Jeffrey were brother and sister. Maybe Richard was married twice or maybe Mary and Ann are one and the same? Mary Ann?
Cheers,
Greg