I am always up for a new machine. that i how I got my new (used) one. My singer broke and took it in to get fixed. ran into a wonderful lady who said that she would sell me one of her old ones. (only 18 months old) her hubby said no more machines until she got rid of one of them. he demand was my blessing. I have my singer still, got it fixed and useing it as a back up.
I would go get the one from your dads and take yours in to be looked at to see if it is worth fixing. If it is then go for it.