I don't know about the overlockers ... but I have a Elna Contessa 415 sewing maching that were my GRANDMA's and she still works beautifully. Great machine, me and her love each other. She is a bit peeved at me for sewing thick soakers with her atm (mind you it could be the fool behind the tool ), but other than that ... she LOVES working.
She can staystich, backstich and zig-zag ... for kids clothes and home use, that's all ya really need.