My 1400 was working OK, and then I oiled it and something started to stick. It did not want to be over oiled and I over oil. Once I cleaned that arm off with alcohol it stopped being sticky.
And taking a quick look at 1774 online it looks to be the same outside as the 1400 with all the knobs in the same place. I am curious, are the built in cams laying flat and horizontal or on their edge and vertical? It probably does not matter to the problems. The 1400 was the middle quality of Sears machines and it has vertical built in cams.