I have the exact same one in a brand new box and was wit the car when I bought it in 2001.

There were a couple of these in a box in the back of HLS30-08323 when I acquired it. The rest of the parts were some fan belts, condenser, the two oil filters, a speedo. cable and some misc. parts. The date on the receipt was Nov. 1979! The totoal on the receipt back then came to about $120.

I have pictures in my gallery.

Mine were in the trunk of a 4dr. 510 I bought in 1981 and the car had been sitting for three years according to the seller.

Cool, thats exactly the same as mine. So it's safe to say late 70s to early 80s?