usually I translate, becouse I love to do it, and I talk with develeper to have only the last string to add.
Only for Neomule, becouse wasn't possible to talk with xanatos, I used the command Find for each string, inside the 4.25 it.RC, manually, lot of work but pleasant, and when I found some string used for 4.50, I manually added.
Generally I remember the stringtables, but when I am unsure, I use the Find command inside the TXT or RC file to find the old one.
If you want I have a log file with some Neo 4.25 functions used on Neo 4.50 too, at least 100 functions.
P.S. (just to joke a little bit)
I am not fool maybe a bit lively and often during the translation I listen GnR, Led zeppelin, Pink floyd and Deep purple