"Sears 41" is the house brandname used for the "Marlin 101".
Checking Numrich Pin Parts Ciorp website on Marlin 101 bolt,
OUT OF STOCK
Breech Bolt, Complete
Firearm Mfgr: MARLIN / GLENFIELD
Firearm Model: 10, 100G, 101
$67.96 (with the round cocking handle)
$129.19 (with the "T" cocking handle)