Well an easy way to narrow it down is take the total number of 1969 Camaros produced (243,085) and divide by number of RS optioned cars(37,733) = about 6.442% X (Z/28) production (20,302) = at least 1308 RS Z/28 cars .
Now one thing to keep in mind is a majority of production were base cars with little or no options, these are the easiest for the salesman at the dealers to move since they have the least options and they are the cheapest. So I wouldn't be surprised if the real number was more like 4000 RS Z/28. A customer that had some money to work with could obviously check off more option boxes...
Here is the website that shows production numbers for 69:
Kinda fun to check out the production numbers vs options
The total number of í69 Camaros built as rally-sports is 37,773. Divided by total production of 243,085 is 15.5%. Still not the best way to look at it as 4,000 or so of the rally-sports were Z10 or Z11. So thatís 33,773/239,085 or about 14%; 2,867 Z/28-RS using statistical interpolation. Itís nothing more than a guess.
Iím with Mr. Miller. After 40 years of involvement with Ď69s to me there is nothing at all rare about a í69 Z/28-RS and I would not be surprised if the number was 25%.