Royal Enfield close ratio gearbox

Here's something for the hardcore Enfield nerds out there. Recently I managed to pick up a spare gearbox for my Enfield twin race bike (the early postwar type with the clutch operating on a scroll mechanism) in order to rob the kick start mechanism from it. The 500 twin racer is bump start only: I have it registered on the road and, quite honestly, having to run and jump on to it to start the beast is an absolute pain in the a***. I live on a hill and the very last thing you want to have to do after spending some workshop time on a bike is to find it is not running after having gotten to the bottom of aforementioned incline.

On dismantling the box fitted to the bike I got something of a surprise. Whereas I had expected just the kick start shaft to be missing (obvious as it is blanked off) I found that there is no provision for a kicker at all - the gear on the layshaft is not cut for a kickstart pawl. What's more it is a close ratio set that raises first, second and third. I've swapped the close ratios out for a pair of gears with kickstart pawl but time will tell if I miss the close ratios and regret the change....

Delving inside the Enfield twin's gearbox this is what I found.
Close ratios and no provision for a kickstart at all.

The HCR code denotes a 1953 box. Many thanks to Graham
Scarth, chairman of the Royal Enfield Owners Club for
identifying.

Here's the inner cover with gearbox shaft blanked off. It's a
neat job and with the close ratios and lack of machining for
the kickstart pawl I wonder if it is a factory part?

And here is the donor gearbox with regular ratios and kickstart.