My Dad recently past away and I inherited two tredles (Singer 29k51) and a (Adler30-1),I to am a leather crafter but not experienced in leather sewing,mostly tooling,but I have made a few quilts so I do know how to sew but nothing like this.PLEASE HELP ,Other than the size differance Is one better than the other in any way? and are parts easier to find on one and not the other?