Yes, I have extensive details on Richard and know pretty much everything except place of birth and parents. Bit of a long ramble about to follow but it will put everything into context.
1. My 2nd Great Grandfather John Foster b 1808. Claims to have been born in Stewkley, Bucks but I cannot find any record of his birth there. He married twice and on both marriage certificates his father is given as Richard Foster (or Forster), profession "Bookkeeper". John was in the army (98th Foot) for many years. He married in Liverpool in 1839 while stationed there, and served in China during the 1st Opium War. On return to Britain he spent time in Eaton Bray where my great grandfather (John, b. 1849) was born. I can only assume he had family still in the area and that's why he moved there. As John was in the army and I have his enlistment and retirement documents, I have an accurate d.o.b. for him.
2. Richard Foster b. 1811 also claims to have been born in Buck/Beds but again there is no record. DNA evidence, while never conclusive, strongly points to John and Richard being brothers.
3. The only John, son of Richard, born in 1808 that I can find was born in St. Luke's Middlesex (now near Old St, London) . D.O.B. Looks correct but there is a massive splodge on the scanned online copies of the parish register right over where the date is recorded! Thanks to lockdown, I cannot make the short trip into central London to check the original
John's parents in that record are Richard (...no profession given...) and Sarah.
4. What appears to be the same Richard and Sarah had another son, Richard, b 1811 in right month and also in St. Luke's. (For completeness, this Richard and Sarah had another son called Richard b. 1802 but died 1806 - not 100% sure of latter date - but explains why eldest surviving son not named after father). I cannot find any other offspring of theirs.
5. More circumstantial but still possibly relevant: I've tried tracking the marriage of the elder Richard and Sarah. There's a Richard Foster and Sarah Whately married 1800 in Hertfordshire. The younger Richard names one of his daughters as "Mary Ann Whately Foster", possibly after his own mother's family.
To sum up, I'm trying to get the evidence to conclusively join the John (1808) and Richard (1811) and I think what I need is the marriage record for the younger Richard that hopefully gives the profession of the elder Richard. If this also says "Bookkeeper". Then I think I've nailed it. Unfortunately, I cannot find a scanned copy online and the transcribed ones don't give detail.
Apologies for long explanation
Steve