RE: Just a little respect for the SPA...
When the issues were in debate for SPA, I suggested a 25 year carryover rule for designs; It got rejected. The one big contention was that newer designs would have a competitive edge over the old stuff. I then mentioned the 'Curare' word and got jumped on again. The pattern designs were pretty consistent to one another until 1975(the cutoff date) when the Curare rolled out which was a fairly significant jump in design and lead to the next generation of ships.