Singer class 7-33 leather sewing, which needle ???

[Constabulary]

4 minutes ago, Jadu said:

An additional problem is that the needlebar hits the presser foot when the presser foot is raised

that's most likely why the former owner has used a longer needle You can either try to lower the presser foot or use a longer needle to prevent this.

[okiwen]

Wow.  That was great to read.  You all are very knowledgeable.  

[Jadu]

To avoid problems I made a modified Lifting Presser Bar for the use of shorter needles.
Now I can quickly change needles with only 1 adjustment, the needlebar.
Without the extra Lifting Presser Bar you will ever make the mistake of sewing without lifting the presser foot. Major damage will then follow.

Thanks for your help!!!