On the date of your bike. Here is some notes for comment:
It seems that Humber were taken over by Raleigh in 1932 (
source)
The serial numbers by Raleigh in the early 1950s are found at the same source
1947: 437689 P
1948: 556894 P
1949: 695051 P
1951: 151179 T
1952: 236530 T
1953: 367369 T
1954: 566722 T
The note with that list explains 'After the war, Raleigh began adding letters after the running number series which restarted when a new letter was used.'
Your frame has the serial 293623H. In terms of where it would fit in into this pattern it would be 1952,
if we assume the same numbering pattern was used and they used a H rather than the T so as to indicate the frame was to be built as a Humber.
So how do we test that assumption is reasonable?
There was a Humber recently advertised on e bay
see here
Its details included 'th frame serial no is 305257h, the oristocrat of all bicycles, genuine leather brook saddle no is b66s, the rims is 26"x1 3/8 raleigh regd no is 832297, the rear hub is sturmey archer 3 speed .word patents made in england. fg.53.8 dyno-four'.
Apart from the spelling and lack of capitalisation, we have a serial number very close to yours, with the H at the end and we have a SA hub with a confirmed production date of August 1953. The bike looks in good original condition with all parts seemingly intact. So the assumption has some support. It would be nice to have a few more Humbers to confirm it.
I would be working on a 1952/53 first sale date, not a 1949.
A check on the date code of the SA hub might also provide a clue as to the date of your bike.
I throw it open for any comments.