I think are a bit of misunderstandings here.
the Mk 22 has 90% the same parts as the Mk 13. it is thus an very good unit to test capability with the Mk 13 and it's missiles, and needs no replacement.
it is also near impossible to replace it with an Mk 13, because it is much bigger. it is easier then replacing the Mk 112 with it, as that one has next to no deck pen and the Mk 13 has a lot, but still it is easier to just build an new perry hull for testing only then what you have drawn now.
the OHP has no ASROC capability as it's launcher does not support that. it is still a better ASW platform then many of it's predecessors due to the fact that the ship carries 2 LAMPS helicopters.
testing the LAMPS arrangement would only really be possible on this ship if you literally rebuild the stern to that of an perry. but, this can be tested on land based facilities better, as the most important influences; the helicopter, the wind around the ship and the movement of the ship, will be independ or different from the perry itself anyways.
for the director arrangement.....
the perry's it less then ideal. the WM egg is placed forward, while it does mainly gun guidance, while the SPG-60 STIR is placed at the rear while it guides the standard missile.
the reason for this is most likely the fact that the egg is more or less a core system which you want close to your CIC, it has the targeting radar for both systems and thus needs coverage for both. this keeps the cables and support systems short and less vulnerable, and thus speeds up processing.
the SPG seems to have sacrificed some end on performance, especially on the lower ranges, for that. most likely the WM does a bit of the work for that field of fire. not also that the earlier versions of the perry, shown here:
http://www.shipbucket.com/forums/viewto ... =13&t=4209 have an entirely different arrangement, and the current one might have been dictated by the lack of electronics space in some parts of the ship
on your ship though, the field of fire for the SPG is worse. the mack leaves a lot less clearance around it free then the mast does on the perry, and the SPS-49 interferes as well. and why would you, when you have an perfectly capable position at the rear, with the cables and cooling in place? the forward position should be suitable for an WM, which might need to be a bit heigtened for the WM to have enough coverage to be part of the FCS.
also, keep this in mind. you have a test ship, which will test the abilities of your FCS. why would you create difficulties like in the ship that would have been really build, if you still need to test if those difficulties arise? depending on the exact year of your design, the exact perry design might not even been entirely completed. it is also always an bad idea to have the perfect angle of the FCS and the perfect angle for the weapons differ. while it might be partially the case on the perry's, you can understand it is normally something you try to avoid
a note is also that I think that the test ship had the systems as it had so the electronics could be placed temporarely in the hangar. in your case, 50% of the ship would need to be rewired. you might also need to expand the internal space a bit for the upgraded (often larger) electronics.
and while the phalanx has been placed in worse positions over the years, it seems a bad thing to do when it is brand new (note that the first line of perry's did not even have it fitted as build) it even seems a stretch to put it on board!
EDIT:
and the latest parts.......
belowdeck parts
USN missile launchers
parts sheets section of the main site
parts sheets section of the forum
and I believe I linked you to the Mk 22/Mk 13 renewed drawings a few posts back, IIRC.......