Using pattern cutting book from 25 years ago (when size 12 block had 26" waist)

[ToriTheStoryteller]

I'm trying to get back into making clothes. I have a brilliant pattern cutting book that I used a lot, the problem is that these blocks that fitted me 25 years ago definitely don't now!

Is it worth trying to grade the blocks up from the book's 12 to 16 or is that likely to lead to too many inaccuracies? Should I just go out and buy some ready made patterns and adapt them to suit my designs?

Anyone had success with grading basic blocks up by 2 or 3 sizes?

Can you make new blocks ?
Commercial patterns bear very little resemblance to clothes sizes.
I am a 14 and regularly cut out an 18 as per pattern measurements

I think I'll have to. I had a bit of a "duh" moment today because the book does have all the other sizes' measurements but because the blocks are based on the size 12, it hadn't occurred to me that I can use the size 16 measurements instead! Then I can tweak certain parts to fit.

I didn't appreciate how lucky I was years ago when I could draft a pattern and it fitted me perfectly!