Spend money on rain water collection as when the Japanese took the water catchments Singapore was stuffed. Improve the border defensiveness. Build hardened air craft hangers buy more modern planes lots of them and tanks that more than a stupid 2 ponder gun that could not use any rounds on troops.
Spend what’s left on training and training. Singapore was doomed as soon as that idiot Percival was appointed along with then RAF fellow who for the life of me name I forget.
When you look at most tanks being built in the period 1936-1941 then very few are using a gun bigger than a 2 pounder / 40mm
PzIII? - 37mm
BT7? - 45 mm
Sauma S35? 47mm
Type 95 Ha Go? 37mm
M3 Stuart? - 37mm
The 2 pounder was by comparison a pretty effective gun - and while some of those had an HE round it was about the explosive effect of a hand grenade at that calibre
I agree that a 6 pounder would have been better earlier though!
Percevils problems was that he knew what was required to defend Malaya and he was only given about a 3rd of it.
He was also surrounded by defeatists who urged him to surrender once the water works were captured despite many commonwealth units still having cohesion and ammo etc
A very detailed report detailing all of the failings and short comings of the Malayan defences was sent back to London in mid 41 (?) and by an incredible stroke of misfortune the weighted secret bag containing said report fell into German hands when a raider captured the ship carrying it (the ship started broadcasting the raider alert message over morse and the raider shelled it killing and wounding everyone on the crew who knew to ditch the bag overboard!) - And they only passed it on to the Japanese the dirty underhanded swine. So at a stroke the Japanese knew 'all of the failings and shortcomings of the Malayan defences'
That would be considered ASB/Axis wank if it happened in story written here!