Ive been doing a little refurb on some Rs 7 spokes for my new runner.
I did 4 then noticed one of them had a slight dent in the inner rim (see left upper of pic)
So I got another and when I had a good look at it today noticed it was different!
My thinking is it must be an RS1600i rim. It is datestamped 83 and had a few differences.
The castings on the face of the s1 rims are, Ford Motorsport, Wheel size, part number and has II stamped on the back of one spoke and Ronal stamped on the back of another.

The RSi rim has Ford Motorsport stamped on one spoke followed by a number, then on the back has date stamp, part number, size and a large Ronal logo.

I weighed one of each and found the RSi rim to be about 0.5-0.7kg lighter (my scales are old )
I thought some people might find this interesting and wondered if anyone new WHY the rim was lighter. Different compound of alloy?
Anyone have any further input?