SINGER 15-91 & 15 CLASS PARTS SOME OF THE PART NUMBER MAY BE DIFFERENT THEY SEEM TO CHANGE DEPENDING ON YEAR BUT ARE SAME PART.  I HAVE A SPRING FOR THE BOBBIN WINDER LARGE SPRING IS NEW #47.  IF YOU HAVE ANY QUESTIONS OR NOT SURE OF PART PLEASE ASK, I AM HERE TO HELP.
THANK YOU,
DUANE 

#1-125263 ROCKER ASSEMBLY,
#2-125281/125298/51229/1253 HOOK SHAFT,
#3-125270/2835/15445 ROCKER#4 MAIN HORIZONTAL SHAFT 125253/15272/15498/125045#5-125458/125460/125461/ HAND WHEEL
 #6-125303/125304/125301/145/125290/391 RACE
#7-125284/462/125330
#8-125021 VERTICAL ROCKER W/SCREWS
#9-125045
#10-125340/125335/51252/1520/175 FORK
#11-15272/570/140511/1520
#12-15498 MAIN SHAFT BUSHING
#13- 125276/15248 CONNECTING LINK FOR NEEDLE BAR TO THREAD TAKE-UP
#14-2070/80011 SPRING PRESSER BAR/WASHER
#15-125377 NEEDLE BAR
#16-125061 PRESSER BAR
#17-2068/453 PRESSER BAR CLAMP
#18-SCROLL FACE PLATE W/THREAD TENSION ASSEMBLY
#19-FACE PLATE W/THREAD TENSION
#20- 2 SCREWS FOR FEEDDOG

#22-125280 MAIN ROTARY DRIVE
#23- 125474/15486/140712 LEVER PRESSER FOOT
#24-125290/391 BOBBIN CASE POSITIONER
#25- 51228 SCREW FOR PRESSER FOOT TENSION
#26- BUSHING FOR HAND WHEEL
#27- SINGER EMBLEM BADGE W/PINS
#28- SINGER EMBLEM BADGE W/PINS
#29-125383 THREAD TAKE-UP ARM W/SCREW
#30-12529 RACE BACK COVER
#31-125302 RACE COVER SPRING CLAMP
#32- 125292 HOOK
#33- SCREW TO MOUNT POWER MOUNT BRACKER
#34 BRAKET TO MOUNT 3 PIN RECEPTACLE
#35- PIVOT SCREWS FOR ROCKERS
#36-PIVOT PINS FOR 125280
#37- 3 SCREWS To MOUNT HEAD TO BASE/BED
#38- 125397/REGULATOR LINKAGE STITCH LENGTH LEVER
#39-SCROLL BACK SIDE PLATE CHROME
#40- BACK ROUND STRAITED PLATE
#41- SLIDE PLATE W/SPRING
#42- NEEDLE PLATE W/SCREWS
#43- SITICH LENGTH COVER PLATE
#44- INSIDE PLATE FOR STITCH LENGTH PLATE
#45- SCREWS STITCH LENGTH PLATE SCREWS
#46- CHROME STITCH LENGTH COVER SCREWS
#47- NEW SPRING- BOBBIN WINDER large SPRING
#48- THUMB SCREW FOR FOOT/BACK PLATE
#49- MOTION KNOB
#50- 171505 CLUTCH LOCK WASHER
#51- LEVER FOR STITCH LENGTH
#52- THREAD CUTTER
#53- NEEDLE CLAMP W/GUIDE CHROME
#54- NEEDLE CLAMP W/GUIDE BLACK
#55- BOBBIN WINDER THREAD GUIDE W/SCREW WASHER BLK
#56- BOBBIN WINDER THREAD GUIDE W/SCREW WASHER
#57-PRESSER FOOT
#58- FEEDDOG W/SCREWS
#59- 2 HEAD HINGE SCREWS
#60- SCREW TOP MOUNT FACE PLATE
#61- 51246 SCREW SET SCREWS TO HOLD PIVOT PIN