My 201 threads right to left, and my 99 threads left to right, and thinking about it 128 is the same as 99 that way. You are correct, flat side should be to the right. I would take of the needle clamp, clean and check every tiny groove and bit behind there. A 201 I cleaned up had the groove in the needle bar packed packed full of dust, and I spend a few tooth picks to get it completely out. Needle clamps can be a bit fuzzy, but they aren't too difficult, the one on my 201 being a bit tricky. I think 128s are the type of machine where it's easy to insert the needle in the wrong way. It certainly is on my 99 and 201. It's odd it only goes in the wrong way? I have to think twice when I replace needle, especially going from one machine to another.
Your 128 should turn out well, it's almost always about cleaning, oiling and more of the same on these. Common replacement parts are usually the bobbin tyre and if the shuttle is missing. I once replaced a spring in the tension assembly on a 99. Grime under the throat plate can mess up in various ways too, and I'm sure going through all the check points will solve the problem.
Last edited by Mickey2; 02-28-2018 at 06:33 AM.