Stock timing curve on a slant 6

Hi folks. I am trying to understand distributor curves, and according to my manual, my 1967 slant 6 engine should have a initial timing of 5 BTDC, a mechanical advance total up to 25 BTDC, and a vacuum advance up to 15, for a total of 45 BTDC max with all three combined. That seems consistent with the information I have found here on the site and around the internet, although I know some people go with higher initial timing and less mechanical. They all still seem to come out totalling around 45 BTDC max in the end.

What I was wondering is if my curve would work well if it looks like this. This is assuming That I use the factory 5 BTDC initial timing.

500 rpm = 5 BTDC initial, no mechanical yet
1500 rpm = 15 BTDC (initial and mech)
2000 rpm = 20 BTDC (initial and mech)
2500 rpm = 25 BTDC (initial and mech)
3000 rpm = 30 BTDC (initial and mech)
3500 rpm = still at 30 because it tops out without vacuum at 30 BTDC.

Does that make sense? Its nice and clean, but it doesnt match the curve in the manual, which advances timing very quickly from 750 rpm to about 2200 rpm and then levels out. It still stops at 30 BTDC with the initial and the mechanical and without the vacuum advance though. Is anyone else running stock initial timing or am I the only one? :D Does anyone have their timing curve mapped out and could post it for comparison?
Thanks!