Can you help me repair this latch post?

Attached is a picture of the driver's door latch post on my '77 B200 Sportsman SE, which I have owned since new and is in pretty good shape. The latch post is composed of the inner post, a thin plastic tube over the inner post, and a thin wall steel tube as the outer part of the post. My inner plastic tube has broken and fallen out, so outer steel tube flops around and the latch won't work properly. Would any of you guys know how to repair this latch post, or do I need to find a different one? Thanks a lot.

latch post.jpg