A Stamp/ branding iron designed

Information for the business: Logo to be made into a branding iron
Brand name/slogan in logo: JAR
Ideas for the visual style: Stamp idea
Preferred colors: Not applicable
Extra notes: My father enjoys woodcraft as a hobby.
As a present for him, I want to get him a custom made branding iron.
The company I am using to produce it need my desired logo produced to size so that they can apply it to their laser cutter to produce it out of steel.

I want a logo that encompasses another passion of his- surfing (coolest dad around). His nickname is Jar, which I also want to incorporate into the design. Here is my idea.

The idea I had is to have the main part of the logo as a surfboard, with one fin swooping down. This will look like a surfboard but also make up the J of Jar. the 'ar' will be alongside the vertical part of the J and underneath the horizontal part of representing the board.

I have uploaded a really sketchy MS paint mock up. Ideally, the fin hanging down would be larger and the 'AR' occupy more space under the board but this is my rough plan

If the whole thin could be placed inside a box (with rounded corners) also this would be great. Obviously, coulours are not important as this is basically a stamp design.