All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
As long as you are able to fulfill your vow, you should fulfill it in the way that you specified it. Allaah Almighty says (what means): {and fulfill their vows.} [Quran 22: 29] The Prophet, sallallaahu ‘alayhi wa sallam, said: “If one vows to obey Allaah Almighty, he should obey Him.” [Al-Bukhari, Muslim and others]
Therefore, it is not allowable to replace slaughtering the calf with distributing its price as long as you can fulfill your original vow.
Concerning slaughtering the sheep, if the vow is related to a condition and this condition no longer applies, then you do not have to continue after the condition ceased to exist. If you vowed to slaughter a sheep every year as long as the shop exists or the like and then the shop was sold, then you do not have to do anything after the shop was sold or closed.
However, if it was an absolute vow (i.e. not specified), then it remains as such, and you have to slaughter a sheep every year.
Allaah knows best.