The other day I was given one of my parents old phones, come to find out it is the "rare" v3re that is giving people headaches (did a lot of lurking and searching yesterday.)
I am with AT&T now, and after calling them to try to unlock my phone to use with their service (I figured they would be more helpful than Tmo where I am not a customer) they blew me off, and told me to call the manufacturer. I ended up calling Tmo right afterwards. I went through the automated hoops to 'activate new account' and once I got a person on the line I simply asked to be transferred to customer service. I was promptly transferred to a CSR who asked me a couple questions, and since I had been a previous Tmo customer in good standing they were happy to take my IMEI and email so that I could be sent an unlock code.
The only question I have is; once it is unlocked, is there a way the new unlocked phone can be backed up and used to flash a locked phone to make it unlocked? I'm not dense, but some of the tech-talk and modding I was reading is a bit over my head.
Sorry no one has responded sooner, probably because the answer is too obvious: No.
There is no way to unlock a V3re except by the method you used. In fact, there is no simple "flash" method to unlock any phone. (That would be too easy.)