You can download english translation for BS2.1.5 FInal: Link to download
If the authors released patches* for this version of BS, then you need to:
Go to that link and Find the latest patch for BS215 FINAL (Do not confuse with the Original version) and there will be a link to the English translation.
*The translation of the last patch contains the translation of the entire mod + new edits.
If you find some bugs of translation or if you would like to improve the quality of our English translation, let me know in PM.