Spudley's tumour removal

This is my Spudley, my special boy.

He is 14 yrs old and loves nothing better than to snuggle up in bed at night and push his head against mine and purr and he'll tap you on the nose when he wants food.
Spudley has diabetes which sees him needing a insulin needle twice a day and regular blood tests via a prick on the ear but he goes into remission with this so I need to check his levels regularly to see if he needs a shot or not and he doesn't complain at all.
Spudley weighs about 7.5kgs (big cat)!

As you can see he has a large tumour on his shoulder which only 12 mths ago he had an egg sized one removed but it grew back to the same size within 6 mths but since his blood glucose was fairly irratic we couldn't operate or sedate him till his levels were settled and since we live such a hectic lifestyle with me working till midnight 5-6 days a week he gets his shot around 12.30-2am and then again sometime after lunch before I head back to work so that didn't happen for months and now the tumour has gotten so big and he's been licking it and put a hole in it so I need to keep it covered now and change the bandage every second day as it gets smelly and yuk.
Spuds went in on Wednesday to the vets with the hope they could remove as much as possible to make him comfortable but it seems after my vet and a specialist looked at it they surmised that to get it out they would have to leave an open wound which being diabetic won't heal so their other options is to amputate the leg and shoulder so they can hope to get most of it and maybe skin graft to close it which has absolutely floored me.
For 1: he is too heavy to carry himself on 3 legs and 2: according to the X-rays there is nothing wrong with his leg or shoulder!
So after a lot of thought I've decided that I want a second opinion so we have now gotten a referral to go to SASH (Small Animal Specialist Hospital) which we went to today.
Dr James saw my Spuds and has fallen in love with the Spudley charm like so many others that meet my boy. He has decided that the plan of action is to see exactly where this soft tissue sarcoma is touching so we have ordered a MRI (which  is not cheap), so far our bill is $3110  and that's before anyone has operated so we will adjust this goal as we find out more.
 With 12 cats ( I'm a foster failure) and 2 big dogs I tend to get plenty of vet bills which I wear but this one has really thrown me and I hate to ask for help but this is for Spudley, to give him the best chance at life.
We shouldn't have favourites but Spudley is mine, he is the gentleman that loves getting brushed and gives the best cuddles. He has never in his 14 yrs gotten angry with anyone and deserves the best.
Ive had to borrow some money to get him in the hospital and when they get the results he will need to get this surgery asap so they will need more so if you can spare some coffee money to help out I'd be so grateful and I know that Spudley would be too.
We thank you with all our hearts for your love , support and anything you can spare to help out.
Love 
Lenore (Lenny), Steve and of course Spudley 
xxxx