Gregorius originally requested the casting tablet at around level 30 without discussing it with Viola. Viola then wanted a level 40 lab text.
I don't think we've actually bought the lab text and casting tablet, just borrowed them off the Tremere, so they'll need to go back before Gregorius wants to use his House Assistance for something else.
I agree with your assessment of the state of my table at the end of Summer 1230. However, I was always guessing as to the level of the first year's Aegis, but have now located a post (https://forum.atlas-games.com/t/character-development/5173/19) which suggests it was probably level 40, in which case the first year's spend should be 8 pawns rather than 6, and the "final" vis total is 30 pawns of Vim.