Well, you have a below avg GMAT Score...there is nothing embarrassing in it...sure you had given your best shot...its just that on that day your luck didnt quite compliment your efforts...many people score less than 500, many take multiple shots...all are part of ultimately becoming a B School student...you r just another one of them and need not feel down/bad...cheer up!
as far as your admit to Birmingham/Kingston is concerned, its true that most of the reputed B Schools obligatorily ask for GMAT score but in the UK is not uncommon for a B School to give admit without a Gmat Score...believe me...its quite common for all the good but not top-notched schools...I do not know about kingston but I can assure you that Birmingham is a decent B School...Off late it has lost much of its sheen to new schools like Warwick, lancaster etc but around 3-4 yrs ago Birmingham used to loom large in the B School market.
Birmingham Uni being the oldest among all the red-brick Universities provoke good amount of respect at the interview table when a student shows Birmingham Uni degree.
I am not advocating against Kingston...Kingston being located at the London got tremendous amount of advantage over Birmingham but had I been in your place I would have accepted a school which finds its place in the FT/EIU ranking.
Birmingham's stats :
FT ranking :-
http://rankings.ft.com/businessschoolrankings/birmingham-business-school#global-mba-rankingsEIU ranking :-
http://mba.eiu.com/index.asp?layout=school_snapshot&university_id=1920471592&mba_program_id=1930471593&university_name=Birmingham%2C+University+of--Birmingham+Business+SchoolKingston stats: not present in both FT and EIU
Hope this helps......
_ Nes