I appreciate the pointers on the clean out, hopefully when the rain stops I'll be able to give it a go. I do believe I'll start with low pressure and see where that takes me.
As far as the compression post, that is what originally came with the boat. I wondered that same thing the first time I crawled in there about a year ago. All of the c-22's of that time period I've seen on sailboatlistings and similar sites with interior pictures have that same post in them. You can see it here in this ad:
1984 Catalina Sailboat sailboat for sale in Kansas
The plan is to get it all cleaned up and then take it out to my buddies hangar nearby in work on it indoors. Thanks again for all the advice.