A Hobie 16 dolphin striker is too long for a 14, although you could probably use the post (center vertical bar).
A Hobie 17 dolphin striker can be adapted to a 14 - it is the correct length and you just need to bend the ends of the rod a bit and cut off part of the post.
However, to install these on an old 14, you will also need to replace the mast step, since the post threads into it and the original 14 step does not have a threaded hole for it.
What you need is the retro-fit kit:

There's one on eBay right now.