I don't think it is a 241. The literature I have says the 241 had 7 inch spacing, plus it didn't have the adjusting crank that came horizontally out of the front center of the main frame like your does. Also, the spools were thicker on the 241. The piece of literature I am looking at is an early one (1957) so could be some of the specs changed. I'd still lean more towards the 252.