Value of NOS RC-115 radiator cap?

[Mr70]

Roto-Safe caps were never installed on our era assembly line vehicles as far as I know.They were produced years later & released later as an over the counter service/customer replacement that went above the federal minimum guidelines of what the assembly line had to install back then.This newly designed cap allowed you to release psi.w/o unseating the cap from an overheated radiator.
Nearly any vehicle that receieved an RC-15 cap in it's day,was OK to use this upgraded designed cap as a safer replacement to the old.It was also much more costly to the consumer,compared to the std. RC-15 used on the line.

RC-115 caps were recommended for:
<span style="text-decoration: underline">AMC</span>
Jeep 1972-77
Dauntless 1963-71 w/V8

<span style="text-decoration: underline">BUICK</span>
1957-69 ALL (except Opal)

<span style="text-decoration: underline">CHEVROLET</span>
1965-72 ALL (except Corvette or Vega w/Closed system)
~Truck~
1960 V8 396 w/o AC
1967-70 &quot;G&quot; series 100-300 w/o AC.
1971-72 ALL 10-20-30 Series.

<span style="text-decoration: underline">Chrysler</span>
1957-72 ALL

<span style="text-decoration: underline">DODGE</span>
1956-72 ALL
~Truck~
1971-72 compact
1972-78 Light truck w/o coolant recovery.

<span style="text-decoration: underline"> GMC TRUCK</span>
1968-72 1500 through 3500 w/AC

<span style="text-decoration: underline">MERCURY</span>
ALL 1976-78 w/o coolant recovery (except Capri/Bobcat)

<span style="text-decoration: underline">Oldsmobile</span>
1961-70 ALL (incl. F-85)

<span style="text-decoration: underline">PLYMOUTH</span>
1957-72 ALL (except Cricket)
1974-78 Voyager &amp; Trail Duster (w/o coolant reserve)

<span style="text-decoration: underline">PONTIAC</span>
1961-72 ALL

<span style="font-style: italic"><span style="text-decoration: underline">IMPORTS</span></span>
AUSTIN 1969-72 Maxi
DATSUN 1974 ALL
ROVER 1968-71 V8 3.5 Liter 3500