Here are some mast thoughts - in no particular order:
I do not know if the MK I and MK II mast are the same are not, but the shroud length and attachments are the same (tall compared to tall, standard compared to standard) according to the product listings at Catalina Direct.
In regard to CP22 shrouds, Catalina Direct says: “Fits both Capri 22 Mk I and Mk II through hull number 1258, built in January of 2012, at which point a new rig manufacturer was used. The new style mast requires different length wires as well as different attachment fittings.” (An historical side note – I seem to own the last CP22, hull 1258, having the “old” mast.)
In another note, Catalina Direct says that Selden is the new CP22 mast supplier.
If, and that is a big if, the CP 22 and CP 25 use the same “older” mast extrusions (they do seem to use the same boom extrusion), there is a mast section drawing in the selected CP 25 Architectural Drawings that are part of the various CP 22 and 25 plan drawings that are published in various places. This mast section is the same general shape of the Dwyer DM-400 in the above post, but is differently sized.
The Dwyer DM-400 is 4 X 2.65 inches, while the Catalina one (from Consolidated Aluminum for the “CAPRY 25”) is 5.000 X 3.292 inches.