Here's an Oz site that may be helpful.
Good luck!
Rb

Here is a link that might be useful: Raising Ferns from Spores

All Osmunda-ferns can only reproduced from fresh spores, at most 4 weeks old.

Older spores do not come up.
regards
Athyriana
www.farngarten.de

that's a good link - I wish I had seen it earlier.

I'm in the middle of my first intentional attempt at growing from spores - totally different type of fern though.

A couple more links I found: fern life cycle here (with photos) and here (diagrams).