I can't comment too directly on an Ariel mast beam/strongback, as the last time I was in actual physical proximity to one I was about 5 or 6 years old...and my Commander was a Commander...

All the same, from the photos I have seen it looks awfully similar to the Triton mast beam/compression posts/diagonal braces...which, FWIW, come out completely with relative ease and are pretty simple parts to replicate. I'd be moved to just dig out the old ones and replace.

Dave