Question: Buddhism arrived after my father died three years later. Do I not dedicate any merits to him? (because the 49 days are over?) Or not continue to pray he go to the Pureland on his own, when I pray and finish my practice?
Response: This is a very good question that also came up at this weekend's retreat in Nanango, Australia. So rather than post this response as a comment, I'll post it here.
In our every lifetime, we have had parents and other people and beings whom we loved and vowed to help. We have also had many beings we have harmed, either intentionally or because we were not being mindful. So we first dedicate or merits to all beings.
After this universal dedication, you can specifically mention your father's name and say your wish that he "be reborn as quickly as possible into the Western Pure Land to end suffering and attain happiness."
Encouraging people to seek rebirth during the forty-nine days is so important because there is great confusion in the intermediate state between lifetimes. We need to try to connect with beings in this state as they are who torn between the last lifetime and the future lifetime. If we can connect, they could catch our encouraging thought to move on to the Pure Land, heaven, etc.
But even after the being has moved on to the next lifetime, he or she will still benefit from our practice. Personally, after my nightly dedication of merits, I voice the wish that my parents, both deceased, will "be reborn as quickly as possible into the Western Pure Land to end suffering and attain happiness."
This practice accords with causality. The cause: our parents gave us this life. The result: we are the filial children of our parents, honoring and loving them even after they are no longer with us.