It may well be 'my' Richard. The trouble is, there were/are so many Seldons in Landkey, and the names seem to be interchangeable, it's difficult to be certain.
Most of my information this far back came from a 4th cousin once removed of my husband, who had done extensive research in Devon personally. I will try to contact him to see if he has progressed further with his research as he is more local than I am. I do also have hard copies of his research, most of which I haven't transferred to my FTM as it wasn't a direct line, so I must check them as well.
Thank you for your help & suggestions, it's made me look at Landkey baptisms again and I've found some more relatives.