what kind of lock is this?

Looks like an old-fashioned bit-key lock. Most likely either warded or lever mechanism. Impossible to tell more from a sketch of the keyhole; someone knowledgable would have to examine the lock itself.

From the location, my first tentative guess would be warded (primarily based on cost considerations.) Is the end of a "post" visible in the center of the circular top portion of the keyhole? If so, this would seem to be the very common/typical warded lock configuration. Of course, this doesn't rule out a lever lock. A person skilled enough to fit a key to an old warded lock, should be easily able to check the type of the lock.

Unless I miss my guess, you are not asking the question you want an answer to.

If I were to make a sketch of keyholes on cars, do you think that would be helpful in defining the type of lock? How about if I were to say it was a big car or perhaps a station wagon?