What front bead sight did my L.C. Smith shotgun have originally, and is a replacement available today?

Unless it was a special order, the Hunter Arms Company used 'press fit' brass beads. Brownells has both brass and ivory front beads. Check items # 661-104-004, # 100-002-149, and # 539-101- 010

Four front sights were available in the February 1, 1939 Repair Price List, installed:

Brass - $0.35

Lyman - $0.75

Marble - $1.00

Bradley - $1.50