Asteroids amputation urgent

This is asteroid, a 2 year old German hunting terrier, originally from Serbia. Unfortunately whilst in Serbia asteroid was inside a building as it collapsed and broke her spine, she will be unable to walk again, a lovely lady payed for all her then vet treatment and looked after her before sending her on to me. However when she arrived two weeks ago we visited my vets as her rear legs were badly damaged by herself whilst in Serbia and appeared to be fused into place. After many tests and several opinions (costing myself £800) the only option for asteroid is to have both rear legs removed as even without her wounds they hold her spine out of line, I was going to keep them wrapped and save the £1300 required myself, however whilst left today as I walked my other dogs she has managed to further injure one of her legs by attempting to chew it off, she has no feeling or notion that they even belong to her. Her feet are now dying which has massively increased the risk of infection and sepsis. The vet has reduced the surgery from nearly 2000 to 1.3k as it is and won't go any lower, if her legs are not removed this week he says her life is seriously at risk.... She's a beautiful loving happy bouncy friendly dog, far too young to be pts and I will happily care for her for the rest of her life no matter how many legs she's got... Can someone please help me get my baby the life saving operation she needs, she's come so far from being trapped let's not give up on her now!