Yes I know it's a collector's vehicle now, but IMHO this tank should receive a few quality of life improvements.
Most of all, two come to mind.
One – increase the ammo capacity to 40-50 rounds.
Two, and this one is more controversial – reclass the tank as a medium (statwise the only changes needed would be slightly better gun handling and health down to 2050).
I want to talk about the latter one for a moment.
Being a heavy tank means 113 gets paired with crap like RU Objects, E 100, 60TP and so on, which is hardly fair considering the only "heavy" thing about that tank is the healthpool and the turret armor, otherwise it is basically an uptiered Object 430 (the Tier 9).
Also, we have Object 430U which, according to flavor text from the wiki, eventually was shelved because the engineers working on it ended up with a HEAVY tank, not an improved medium, and they had no need for one when they had the IS-8/T-10. So for all intents and purposes the 430U should be a heavy too, yet it is not because lol WG. Of course let's not forget the 430U is superior to the 113 in basically everything but health, but that's a bonus.
Lastly, this would be not the first time WG makes an unhistorical reclassing. We had one in recent times – the T54E1, which went from medium (what it was IRL) to heavy.
With the upcoming buffs to the 121, I honestly doubt WG will do anything with the 113 anytime soon, but I do hope that day will eventually come.