Is it permissible to transfer the amount of a vow to another mosque that deserves the same thing or its maintenance, or to contribute to building a new mosque in another country that bears the name of the first mosque, especially after being unable to fulfill the vow to the first mosque due to financial circumstances and because the vowed items have already become available there?

The basic principle is the obligation to fulfill a vow of obedience to its designated recipient. However, if this becomes impossible, it is permissible to redirect it to another recipient according to what is deemed to be in the Islamic interest. Therefore, you can redirect the vow to another recipient since someone else has already fulfilled what you vowed for the mosque, such as performing maintenance on the mosque with the same amount of money or building another mosque. It is not a condition to name the new mosque after the mosque for which you made the vow.