Dear Master Peter,

Can a merit be dedicated to a deceased person who had died few years ago by performing animal liberation on his behalf? 
Looking forward to your advise. Thanks.

This is more merit to the lving than the deceased.

About good deeds, there are 3 types of gains from 3 types.

1.    Wealth. When you give wealth (财布施) to the needy you will gain wealth. It does not matter how much you give. It is your heart that is matter.
2.    Health. When you provide love and shelter (无畏布施) for others your health will improve.
3.    Knowledge. When you pass on your knowledge (法布施) you will be wiser.

But you must always carry out the above waithout asking for returns. Do it for three to 3-5 years you will see the good effects and changes on your luck.

Cheers.