I've just talked to Mr. E. Meier from Meier-Motors ad asked him about cold-start damage on the DB601.
(
http://www.meiermotors.com/ )
He told me that he started to work as a apprentice on the DB601 and that all damage from a cold start would just reduce the time between overhauls.
Depending on the state of the engine one could experience a seizure during the take-off run or reduced power from worn bearings if the engine was mistreated this way.
The time between engine changes on a bf109 was usually 25h, but a Staffelführer could extend the lifecycle of the engines of his Staffel by careful handling of the engines up to 50h. (i.e. cruising at 300 km/h)
All pilots during that time took extensive care of their engines, using high or emergency power settings only when really, really needed.
He also told me that it takes 90s for the oil to reach the last bearing in the DB601 (about 80s in a RR Merlin)
The oil used during the war was sae100 or sae120 single viscosity and really stiff when cold.
The Jumo211 of the Ju87 had a equipment for cold start that allowed to inject 20l fuel into the engine oil for thinning it, the fuel vaporing when the oil became hot.