Vintage "Blade Master" Shaving Blade Sharpener for Safety Razor, 2 Pack with Box

Description

Vintage "Blade Master" Shaving Blade Sharpener for Safety Razor, 2 Pack with Original Box.
Text on box reads:
"The Ideal Blade Conditioner for Streamlined Shaving"
"Blade Master Magic Black Box Conditions Standard Double Edge Blades"
"Avoid Shaving Soreness; Even When Fresh Out of the Wrapper; Condition your blade!"
"AMAZING PROOF ; All Blades, New or Used, Need Conditioning"
"Small portion of ordinary NEW double edge blade. See those jagged teeth due to mass production. Same blade after having been used ONCE. Hard to believe but the picture proves it. Same blade after conditioning on Blade Master. All nicks gone, - blade is BETTER THAN NEW."
Auction includes both Blade Masters; one with brown and one with red wooden bead. Just the one packing; see one end is open without flap, in photo.
Condition is "Used".
Shipped with USPS First Class.