Rob,
The Pumps with the straight-grooved feet were as per pre-war SS Jaguar, and postwar Mark IV and just into the earliest 1949 Mark V. Pre-war pumps had VEVO branding stamped into the top-surface of the round end of one or both of the straight grooved feet, but during Mark IV period no branding at all, albeit I cannot discount the earliest 1945-46 Mark IV. From mid-1949 onwards, up to an including the last pumps supplied to Mark V and all XK120 the feet were changed to have the diagonal (or Chevron) grooved feet as per your Mark V pump pictured.
As before, SS Jaguar and Mark IV up to April/May 1948 had their timber handle clear varnished, but thereafter it was painted black - again as per my picture and your Mark V pump.
The other major change was the boss on the lower end cap into which the flex (hose) screws for SS Jaguar and Mark IV and up to mid 1949 Mark V pumps has a ‘special’ 11/32" BSC (Cycle) thread, but thereafter was increased slightly in diameter to be a ‘standard’ 3/8" BSC thread - this of course is easiest to measure on the end-fitting of the matching/original flex. This thread change does not exactly align with the change from straight-grooved to chevron-grooved feet.
The 11/32"BSC flex fitting is round, with two grooved row grip as per pic…
The 3/8"BSC flex fitting is a more commonly seen 1/4"BSF hexagon, with the clips and braided hose remaining the same…
I gave up trying to find any supplier world wide who could supply accurate reproduction flex - both fittings, clips and braided hose. So I ended up having a length of accurately reproduced braided hose made here in Australia, that is colour matched GREEN dyed cotton (no nylon) as my research says was consistently used SS-Jaguar/Mark IV/Mark V/XK120. The original braided hose invariably has chemically degraded to various levels green towards yellow/khaki as apparent in my two original fittings photos, so I restore flexes by re-using original clips/fittings with a length of my new reproduction braided green cotton hoses.
The main pump can of course be easily restored (if in undamaged/complete condition), thus now totally feasible to have a ‘concourse’ condition tyre pump and flex, that is accurate/authentic for any model SS-Jaguar/Mark IV/Mark V/XK120 - all Jaguar Part Number C.997 despite the evolution/changes in manufcature/apperance over this 1936-54 period…