goto e-gunparts.com, they should have what you need.
try gunbroker.com they might have parts
100 USD or so
There is 1 on gunbroker.comStevens Mod 39A / 59 A,B,C .410 shotgun bolt Auction # 147552744
No published sn data.
$100 to $150 depending on condition.
From the 1930's through the 1950's.
@ 100 USD