These and many more versions, Flakpanzers, assault guns, flame throwers, recovery and command vehicles, even a Swedish army APC. One thought I had was along with the BREN and BESA machine guns the UK selects (or even co-develops) the TNH export version of what became the LT vs. 38 / Panzer 38t. Not as far fetched as it sounds as when I was looking up dates to start this topic I found the following in Wikipedia:
"The British Royal Armoured Corps (RAC) had one trial model delivered on March 23, 1939 to Gunnery School at Lulworth. A report stated, the "(bow) gunner could not sit back comfortably as the wireless set was in the way of his left shoulder." The report also stated that due to the shudder while the vehicle was on the move, it was impossible to lay the gun. Even at the speed of 5 mph accuracy was poor. As a result, the British did not purchase the Panzer 38(t) and the trial model was returned."
I had been thinking of a totally hypothetical UK procurement and license production as a replacement for the Mk VI Light Tanks and supplement for the Cruiser and Infantry Tanks, with of course the obligatory shadow plant being set up in Australia. So to all the German permutations we can add just about everything the Commonwealth did with the various carrier designs, Mk VI Light Tanks, Cruiser Tanks and even the Lend Lease Stuarts etc. The 38t would have retained their 7.92/8mm MGs but likely would have swapped the 37.2mm for a 2pdr and maybe a 3"CS version, 95mm CS or even a 25pdr SPG would have been viable, a 6pdr or 3" TD and Kangaroo APCs.
The reliability and simplicity of the 38t means that, so long as sufficient vehicles could have been built, the UK may not have required as many (or any) M-3 Stuarts, maybe the US could have concentrated more effort on their mediums through to the excellent M-4. Even reverse Lend Lease (Canadian or Australian built) 38t's in the early years of the war or even an evolved US built version.
Just some ideas.