Vintage RC airplane engine motor H ? Spark Engine 1950's

Description

Selling for local estate, found stored away in closet.
I'm selling 8 different engines this week from same estate.
These vintage engines we're all in same box, w/note that they could be rebuilt.  This guy was in his 90's and didn't throw away anything he could reuse.
I've only tested for compression, nothing further.
Each of these spin free and have compression.
See pics for details.