1982 300D won't start -- is engine turning fast enough?

[hawkwing]

I'm trying to diagnose a no start issue on a new car, here's a video:
https://www.youtube.com/watch?v=xff8UAx_tQE

and here's the car history

* bought the car 2 weeks ago (still excited!). started without issue on first or second try every day.
* last week it ran out of fuel (oops, sticky fuel gauge)
* two nights ago I left the parking lights on by accident and the next morning it wouldn't start. it also frosted that night for the first time this year (this is Alaska).
* yesterday I charged the battery and plugged in the block heater, it still wouldn't start. 55F during the day.
* today I replaced the battery (new) and checked the following:
** glow plugs getting 12V -- yes (PO says they're new, haven't verified)
** fuel to each injector -- yes
** air in injector lines -- no
** air filter -- ok
** block heater -- ok
** compression -- don't know. don't have tools to do the valve adjustment yet

I'm not sure if I've done something or it's just a coincidence that it won't start after draining the battery, but even with the new one it sounds the same. On another thread someone suggested that an expert could identify whether it's turning over fast enough or not with a video. Any thoughts? I haven't checked the starter, I'm not even sure where it is.

thanks