The spar I made yesterday was flawed, it was not completely square. Cut off one rs-5 and re-glued it.
Made another spar that is identical, this is for the rudder front spar.
The front spar of the fin is made the same way except the rs-5 is replaced with rs-1. Now that both spars are made I can start making the ribs tomorrow.
Here are some pictures of the completed spars: