Cal 21 Removing the Keel

Hello all,

I just acquired a 1970 Cal 21. Considering its age I would like to drop the keel and fully inspect both it and the trunk before launching it. However it is on a trailer and I'd rather not put it in the yard as the closed full/self service boat yard is a good ways from me.

So my questions are these:

First, does any one know of a safe, inexpensive way of jacking the boat up without buying boat jacks/a cheap place to buy boat jacks. I have thought of just putting up on blocks but this makes me nervous having someone in the boat in order to lower the keel etc.

Secondly, dropping the keel out of the slot doesn't seem too hard provided caution is used, but any advice on this is welcome. What more so concerns me here is putting the keel back into the slot... any thoughts are appreciated. Pictures/ detailed descriptions of the process would be fantastic though

Also if anyone knows the dry weight of the boat that would be great, as well as the mast clearance height. There are a lot of bridges around me and although they all have a very high clearance, I still like to know

Thanks in advance