So many repair people are stubborn and think they know it all about any machine. I know from experience most get mad when they find out the customer knows more and can prove it. One Featherweight man was very put out when he tried to sell me a led light for my featherweight. I told him it wouldn't fit because I had the 'white one'. He about laughed in my face. I brought my machine in and said go ahead put the light in. He couldn't, didn't fit. He said he never knew that. If you find a good repair shop you are blessed.