Beyond any doubt Henry Revell of Fife and Swinford had at least one brother and perhaps more. In your analysis you mentioned that you believe he had a brother named Robert Revell of Long Crendon.
In my analysis I believe one of his brothers to be Roger Revell who held lands in at Teffeld, Rokesle Coves and Buckeby, Northampton. 
You state the Henry had a son, Robert of Swinford who was probably married to Cecelia and had lands in Chester. I show Henry married to Margaret Orm d/o the Lord of Abernathy.Henry was taken prisoner at Alnwick Castle in 1174 and later exchanged.  
I show that Henry’s son, Robert married Joan Wapenbury  a widow. Henry held lands in Norfolk, Essex & Northants (Liber Niger) and was Lord of Scalford. I also show that Henry had two additional sons: Richard Revell of Langport and Curry-Revel and William Revell of Wincanton. I am not aware of a marriage to Cecelia.
There seems to be some confusion: Robert did marry to Joan Wapenbury a widow ,with a daughter Alice. Robert’s son Hugh Revell married Alice Wapenbury, daughter of Joan and her now deceased first husband. Hugh & Alice Revell had a son, William Revell  William Revell of Newbold-Revell  who was father to Robert and Sir John Revell (senior) as mentioned. Robert, brother of Sir John (senior) was father of William of Kent, the Bellmaker. Your message seems to confuse these good folks.
I have formally dropped Agnes Revell as a daughter of Sir John Revell. As it turns out Elna Revell married Sir Robert de Gresley and they had a daughter, Joan who marriedRichard d Boteler and they had a daughter Elizabeth Boteler who married Ralph Bellers.
Brownsover was passed down this line until Ralph gave it to Thomas Bellers per CR 162/65 dated 25 March 1412.
Sir John Revell (referred to as senior in your message) did have a brother, Robert and he did inherit land at Buckeby as you say. He also had a son, William as you also reported. I did not know the name of his wife but they had a daughter, Joan who married Geoffrey de Edmunscote  Reynolds.I do not know of a second marriage of Joan to William Attilburgh.I believe that William also had a son, Thomas of Edmunscote, but can not locate a brother, John as you report. However, if true would make an interesting connection to the Revell’s of Wales.
It is true that Joan kept her maiden name, additionally she and her husband had a son named Richard Reynolds, who also kept the name of Revell rather than Reynolds.Richard (Reynolds) Revell of Emscote, married 1st to Margaret d/o Robert Hugford. 7 Henry IV (1406) and 2nd to Agnes Unknown.Now for the interesting part: This Richard (Reynolds) Revell is the father of Robert Revell born in 1432 who was a grocer, alderman and Sheriff of London and Middlesex in 1490, who married twice; fist to Alice Unknown and secondly to Margery Hill who after Roberts death married 3rd to Sir Ralph Astry, Sheriff 1485, & Mayor of London (1493-4),a fishmonger.Robert was buried in theChurch of St. Mary Hill in BillingsgateWard in London.
Sorry, but the footnotes did not transmit properly. I went back and added notes which should be deceranable.
1. Testa de Nevill (Liber Feodorum –The Book of Fees)
2. Scotland’s Historic Heraldry, page 108 by Bruce A. McAndrew. Henry married Margaret d/o Orm.
3. The Norman People and Their Existing Descendants in the British Dominion, Second Edition, Page 376 published by Henry S. King & Company, London. Also see the Ancestor, a Quarterly Review of County and Family History, Heraldry and Antiquities dated 10 July 1904, page 106.
4.See The History and Antiquities of the County of Leicestershire by John Nichols.
5. A History of the Court of Sussex, Volume 7 by L. F. Salzman. Joan is married to Robert Ryvel, daughter
6.The Norman People and Their Existing Descendants in the British Dominion, Second Edition, Page 376 published by Henry S. King & Company, London.
7. The Battle Abby Roll with Some Account of the Norman Lineages, Volume 3, pages 62 & 63 by Catherine Lucy Wilhelmina Powlett Cleveland (Duchess of Cleveland).
Sates that William is a son of Hugh Revell.
8.The National Archives; Ward-Boughton-Leigh at Brownsover, Reference CR 162/57. William lease all his lands at Brownsover to his mother Alice and his sister Dame Agnes.Should he die his son John shall collect in his stead dated 25 June 1294
9. A Descriptive Catalogue of Ancient Deeds in the Public Records Office, Volume 4 page 286, paragraph Northampton A 8290 by the Public Record Office. Joan named adaughter of William and married to Geoffrey de Edmundscote.
10. A History of the County of Warwick: Volume 6: Knightlow hundred (1951), pages 164-167. William Rivel left a daughter Joan who married Geoffrey de Edmundescote,
also called Reynolds, and their son Richard took his mother's name of Rivel and in 1408 conveyed the manor to Robert Hugford and Joyce his wife.
11. Pipe Roll Online, Special CollectionsCourt Rolls SC 2/194/104. Names Richards wife as Agnes in 1455.
12. The Aldermen of the City of London, Volume II by the Rev. Alfred B. Beaven, Eden Fisher & Co., Ltd., London, 1913.