Al Fincham acquired this eight for me in 1981 while he was in the U. K. (probably directly from Rocksport). I acquired a second one on eBay from Julia Bastonein 2008. I acquired another in 2017 as part of Bob Thrun's collection.
The Rocksport is cast from phosphor bronze. Mine is 166 mm tall, 80 mm. wide, and 17 mm. thick. The rope hole is 55 mm. high and 55 mm. wide. The top center thickness is 16 mm. The shaft length and width are 63 mm. and 27 mm., respectively. The eye measures 21 mm. by 21 mm. My eight weighs 705 g.
The front side of the shaft has "ROCKSPORT" in raised letters.
The Rocksport is one of the "other eights" that do not fit into my normal categories. It is far too heavy to use on a regular basis. It is thick enough that it "should never wear out," but it is also heavy - over 700 grams! That makes it about 5 times as heavy as it should be and 16 times as heavy as the lightest eight in my collection (the CMI Ultra). Despite the Rocksport's overall bulk, the eye is too narrow to accept two full size locking carabiners.