Nice looking engine. There are a few of us with running CoBras out here. Search YouTube for “Crosley CoBra” and you’ll come across some of my videos.
Before you start it, fill the block with water to see if there are any leaks. The water also provides a heat sink. The thin metal block heats up FAST and can be damaged quickly without water to soak up the heat.
If you do discover any pinhole leaks, some folks have had good luck with K&W block sealer. I chased a roundside pickup heading into Wauseon last summer with the tin block that was very, very sprightly. The owner told me later he’d treated it with K&W and had no problems.
As a running display engine, this will be a hoot at car shows!