Straight from the Insider and the supertest client.
Japanese Tiger I (doesn't have limited MM, a Japanese heavy tank premium)
"In 1943, the Japanese ambassador to Germany attended the Tiger field trials in Henschel. After that, the company was ordered to transfer all tank documentation to Japan. One disassembled vehicle was sent to Bordeaux on 14 October 1943 to be delivered to Japan by submarine. However, the eastern ally of the Wehrmacht was never able to establish its own production of Tigers. The vehicle was never delivered and this adventure cost 645,000 Reichsmarks to Japan, while the original cost was 300,000 Reichsmarks."
Kanonenjagdpanzer (replacement of the Jagdtiger 88 in stores it seems, unlimited MM)
"The first Kanonenjagdpanzer prototypes were produced in 1960 by the Hanomag-Henschel company for Germany. The production continued until 1967. A total of 770 vehicles for Bundeswehr and 80 for the Belgian Armed Forces were built. However, since 1983, this model was deemed outdated. Some of these tank destroyers were converted into artillery observation vehicles, some others were refitted into anti-tank guided missile carriers. However, some Kanonenjagdpanzer, also known as the Jagdpanzer Kanone 90mm, remained in service until 1990."
VK 45.02 (P) Ausf.B7 (mini-Maus on tier 7)
"Variants with forward-mounted turret and rear-mounted turret were designed by Ferdinand Porsche. The tank never saw mass production."
"The Cromwell was developed in 1941–1942 by BRC&W. A total of 1070 vehicles were mass-produced from late 1943 through 1945. They were extensively used by the British army in the Northwest Europe Campaign of 1944–1945."
"In 1934–1935 the design bureau in Kharkiv Locomotive Factory developed the artillery modification of the BT-7. The new elliptical turret was equipped with the 76.2-mm CT-28 gun. In addition, some vehicles received new radio stations. A total of 155 artillery BT-7s were manufactured. The vehicles saw combat on the Karelian Isthmus, in Manchuria, and during the first period of the Great Patriotic War."
IS-3 with Autoloader
"In 1956–1957, the Military Armored Forces Academy developed a thesis project of loading system on the IS-3 and T-10 heavy tanks. The IS-3 variant provided double-row ammo rack with automatic loading system. The crew was reduced to three members: commander, gunner, and driver. The turret was redesigned in order to allow the arrangement of loading mechanism. The vehicle existed only in blueprints."
Very oddly enough, the supertest files contain traces of two interesting vehicles:
Strv 103 A (marked as "HeavyTank_EU_TECH_Tier_X")
IKV 91 with following description: "Designed and manufactured by Hägglund and Söner, the LKV 91 was originally designated as a light tank, and later into a tank destroyer by Sweden Armed Forces. The first prototypes of the LKV 91 were completed in 1969 with production running from 1975 until 1978 with a total of 212 vehicles produced."