Definitely not the N. I owned a B-15R (the modern reissue before the Heritage line) that had those switches. I played a few S years ago but the B-25B definitely had them. Point being, the B-15S/B-25B was always slightly different from the classic B-15N to begin with due to the different tube config. I left my B-25B stock with 7027As; I never went the 6550 route.
So it's nice that what is being offered up is not just a typical '60s B-15N clone.
EDIT:
OK, I'm wrong. Looks like the later 70s models had those switches. TIL.
1978 Ampeg B-15N Portaflex 30-Watt 1x15" Bass Combo | Tyler's Gear Outlet | Reverb
I believe they were actually added in '68. There's a 1970 model for sale on Reverb right now that has them.
If you need an Orange as well, I ordered an illusion orange Slampegg for January that I'd promise to not change/if you wanted to ship it early