My poverty spec 1.3cdti meriva has the tiny 2 line mileage display between the speedo and rev counter, i want the full size bord computer type display,

So i have bought an IPC from a 2011 Insignia 2.0 CDTI, this was the cheapest IPC with the full size display that had fast shipping to me (no meriva 1.3 cdti IPC's with full display available)

I am aware it might not work, but have willingly risked 25 on this project.. the speedo goes 20 mph more than my one (the tiny engined vauxhalls speedo's go to 140/150 mph, but struggle to get past 100 tbh) where as all others speedo's go to 160/170 mph)
Would i be right thinking the speedo will display correctly.. as it just received the speed pulses (i presume a square wave signal from one of the abs sensors) and the IPC's software/hardware will move the stepper motor the right amount (if the needle will read low, i can swap the speedo card over from mine)

I have read on another forum of someone who got a full size display IPC, plugged it in and it all worked.. except the mileage displayed ----- until he had it decoded and married to his car using a tech2.

Now, as my car dosent have the mpg displays anyway, i imagine i'll need a bit more work.
i have also ordered a bord computer indicator stalk so i can operate the menu's on the larger display.. the one with the menu and set/clear buttons on it.. i'm hoping that will be a plug and play item... BUT, can someone tell me if it needs another wire adding, and if so, where to run the wire to please? (read that adding a cruise control stalk to other cars some needed a 3rd wire, i already have cruise, steering mounted buttons for that)

So.. if the IPC works on my car, i'll need it coding to get the mileage to display... also i will need the bord computer functions activating (not sure i can do that with my vaux-com clone, trying to do it pretending to be an astra J or insignia in vaux-com i got the options to enable mpg displays etc, but trying to add them to my current IPC made me lose some of the lights (cruise white light, asr off, eco shift light, comfort close window screw up indicator etc)

Anyway.... i am in Chester for the next few weeks, noticed that Pecky isnt taking any bookings atm, i know of someone else who can do it, but he lives 250 miles away... i'd be ok with driving the 100 or so miles to Pecky to get it done, but further is a bit much as i am looking after my GF who's broken her foot, so can't be away for too long)

but i was wondering.. i read about needing the eeprom read.. i presume it needs de-soldering to read it (and typical, my solder station and electronics stuff is in storage) but what would happen if i desoldered the eeprom from both IPC's.. and swapped them over? would it screw everything up, or would it make it think the insignia IPC is now the meriva's IPC... tho would it think it's still the poverty spec display....??