Well, it looks good to me. I have a few ideas. First is to use a Guinevere-style plate load on the final stage. It offers the high drive capability and a little more free gain without interfering with the RIAA parameters.Second, I'd suggest the 6BQ7A/6BK7B valve. It is inexpensivew and a little higher gain. Cg-a is comaprable to any of the mentioned alternatives.
regards,
Douglas