My sister gave me a singer merritt 2404 sewing machine. she is not a sewer and said the only thing it was ever used for was to sew an apron. What can you tell me about it. she did not have the manual. what size bobbins does it take. is there anything special I should know about oiling it. If you have one how much did you pay for it. any help you can give me would be greatly appreciated.