This can give you a starting point. Keep in mind though that this is a L52 (measured as rifled portion) barrel, not an L68. The intended cartridge for the tank gun may have been different as well.
For purely wargaming purposes this was posted by MicroMark on
tanknet. Though again not for a L68 barrel.
APDS (1953) 33cm/100m; 29cm/1m, 26cm/1.5km, 24cm/2km
APCBC 24cm/100m, 20cm/1km, 18cm/1.5km, 16cm/2km
APCR 32cm/100m, 26cm/1km, 22cm/1500m, 19cm/2km
Sabot values will depends upon which type of round is it supposed to represent APCR or APDS.
HEAT can be boiled down to diameter and sophistication level. You can get a decent idea by taking the penetration of real rounds and dividing them by the diameter of the HEAT shell. You can use the ratios obtained to work out a reasonable guess for the 10.5cm gun at the assumed sophistication levels.