Did I understand toki correctly?

1. 国へ帰るとき、かばんを買いました。
2. 国へ帰ったとき、かばんを買いました。

According to the book I'm reading, they both translate to: I bought a bag when I went back to my country.

Now the nuance, if I understand correctly, is that 1. is saying that "on the way" to the country, she bought a bag. In other words, she bought the bag en route but before she arrived at her country. And 2. is she arrived at her country and then bought the bag.

Is my understanding correct?

In short, yes, you're right.

Yes, I understand that 2. is she arrived at her country and then bought the bag in her country.

But, I think 国へ帰るとき give the impression that "when I'll go back to my country" strongly.
When I hear she say so, do I think 国へ帰るとき means "before she arrived at her country"?
If the latter half is past form like かばんを買いました...?
If she went back to her country and return this country again, and then she say so to me in this country.
Yes, I think she probably bought the bag in this country before she went back to her country.

1. Before returning to my country, I bought a bag.
2. After returning to my country, I bought a bag.