These old Landis #1 are great for heavy & thick material because the only needle made anymore is a size #26 for #346 thread.The needlebar is not adjustable so the only other needle that would work would have to be a longer one you could shorten.If I remember correctly it's around 3" long.Parts for it will be hard to find too.If you do buy it I know where you can order needles from.
Might just be thread jammed in the hook,put some oil all the way around the outside of the bobbincase & spin the shaft back & forth & it should free up.
This issue has been resolved.He brought it back to us & since he had a Ferdco 440 for some unknown reason he thought the top tension should be as tight as the Ferdco .So we adjusted the top tension (loosened it a lot) for him & he sewed on a lot of leather & was so happy he bought a CB3200 for his holsters.
Looping underneath is always upper thread either too loose or incorrectly threaded,with a home machine you could be using a thread to large for it can also cause looping.So double check the threading & then keep tighten the top needle tension as far as you need to get it to stop looping.
Either it's not threaded correctly or the top tension is too loose. So double check the threading first, when you know for sure it's right then tighten the top thread 1/2 a turn at a time until it stops.
IF it's threaded correctly,the tension is tight enough ,make sure you pull the handle all the way forward & back & you always hold the thread for the first 3 stitches it shouldn't be jamming up.Miss anyone of the above & any Industrial might jam.