No joy for moving Verizon iPhone 4S to T-Mobile

Question

My questions on this topic have been answered but I wanted to post back for the benefit of anyone trying to follow.
It has long been known that you could not use a Verizon (CDMA) iPhone 4S on a domestic GSM network such as T-Mobile.  The hardware is capable (more or less) but the phone is software locked against using GSM domestically.  But I had hoped the recent CTIA agreement amongst the carriers might have changed this situation and allowed me to use my wife's old Verizon iPhone 4S  on my T-Mobile account.  At one point both carriers told me that it should work and was not difficult.
That was bad information.  It is NOT POSSIBLE.  Although Verizon was helpful in getting my iPhone 4S enabled for international GSM usage, this was not sufficient.  My new T-Mobile SIM is rejected as "Invalid", just as it always has been.  I spent time on the phone with all 3 entities this morning and eventually both Apple and T-Mobile confirmed that the transfer of an iPhone 4S from Verizon to T-Mobile cannot be done.  (T-Mobile's "BYOD" page certainly does not divulge this.)
This was a huge waste of time.  I wouldn't have started down this path if the simple facts were available and the various reps didn't incorrectly keep encouraging me that it would succeed.  Your mileage may vary, but trust my experience:  I spent hours only in the end to confirm the old information that the change is simply not possible.
There might be some for-fee vendor that can make it work and I would love to hear about anyone that had success that way.  For now it makes more sense to give up and move on, and sell or trade the phone to someone that can use it. 

Answer 1

Since the prohibition for use on a domestic carrier is flashed in the phone itself there is no way to work around this. None.
If you had called AppleCare in the first place or gone by the advice here you would have saved yourself a lot of time. Apple has no stake in who you use your iPhone with. T-Mobile wants your business.
Sell your iPhone but before you do put it in DFU mode (Google it) and Restore it as a new iPhone. After that turn off Find My iPhone in iCloud then log out from there and Settings > iTunes and App Store and turn off iMessage and FaceTime.
If you buy a used iPhone 5 you will need to ensure it is an AWS capable phone to use it with T-Mobile. The model numbers are the same so the only way you can test this is to make sure you bought a late model iPhone 5 Model A1429 or to try it with your T-Mobile nanoSIM. If you go with a 5c or 5s unlocked or T-Mobile iPhone you will have no such issue.