A vehicle that got mentioned earlier but (AFAIK) hasn't been statted is Brazil's X1 Pioneiro. It's a massively upgraded Stuart tank. Brazil had received over 400 Stuart tanks after World War II, and by the 1960s they were pretty obsolete. Brazil decided to upgrade the Stuarts rather than try to buy something entirely new.
The tanks chosen for the upgrade package were torn down so completely that the armor was cut off the vehicles and replaced. They were lengthened slightly and an enlarged engine compartment took advantage of that extra space. The suspension from an M4 artillery tractor was copied to give the new tank more modern running gear. The turret ring was enlarged and the tanks received a French low-pressure 90mm gun as their main armament, with a pair of M1919 machine-guns (one in the forward hull, one coaxial), and a pintle-mounted M2HB. New radios were also included. The new tank weighed 17 tonnes, and was extremely fragile but capable of resisting light autocannon fire. A total production run of 52 tanks were upgraded with delivery of 17 in 1977 and 35 in 1978.
Mass: 17 tonnes
4 crew (driver, co-driver, gunner, commander/loader)
HF 14 - HS 5 - HR 5
TF 6 - TS 6 - TR 4
260 HP Scania D223L V6 diesel
Tr Mov 154/92
Com Mov 25/15
Fuel capacity unknown, probably more than the Stuart's original 340 liters
520 km road range
90mm CN90F3 (no APFSDS) (18 rounds in turret, 10 in hull)
2x M1919 machine gun (1 forward, 1 coaxial, 1250 rounds each)
M2HB machine gun (commander's pintle mount, 750 rounds)
The X1A1 was supposed to be a more lengthened X1 to give additional room for ammunition. That stretch ended up ruining the tank's maneuverability because it was too long for its width. Instead, a new-build light tank was made to similar specifications, the X1A2 Carcara. 24 of the X1A2 were built before Brazil decided to shift focus to upgrades on its M41 Walker Bulldogs.
Changes:
21 tonnes
3 crew (eliminate co-driver)
Change 90mm ammunition to 24 rounds in turret, 44 in hull (still no APFSDS)
Eliminate forward M1919
Engine horsepower increased to 280
Tr Mov 157/94
Com Mov 26/16
Increase fuel to 600 liters
Increase road range to 600 km
Variant: the XM3D1 was an X1 that replaced the turret with a Maxson quad .50 AA mount. Remove the 90mm gun, the coaxial M1919, and the M2HB and replace them with 4 M2HB in a turreted mount. Only one of these was built in real life, but they'd make a useful supplement to an X1 or X1A2 formation and likely be very popular with PC groups. Allegedly it was also fitted with the
TCM-20 variant of the Maxson, but I haven't seen photographic confirmation of this.
The X1 tank family started being phased out in 1988 and appear to have left service completely in 1994, making them a good candidate for oddball vehicles appearing in the Twilight War.