those figures are about right although i thought a 172cup was 1020kg being 79kg lighter than a 172MKII at 1110kg, the 182 20kg lighter (no spare wheel or kit) at 1090 (which then ties in with your KG figure and the 182cup was 1075/80kg so that ties in perfectly.
so id say 172cup 1020 , MKII172 1110kg, 182 1090, 182cup 1075, MKI (depending on bonnet) 1060 kg although newer one was a bit heavier but only marginally.
also a 225cup is indeed 1345kg as you mentioned so out of interest what is a 225cup with recaros ?? how much to two side airbags + detonation kit etc.. and the recaros weigh against the full fat full leather beasty`s ? id wager at Least 15kg which was the weight diffo between a 182trophy and a 182, however the seats in the meganesport are deffo bigger and fatter so we could be talking more
so 225cup + recaros is 1345kg - 20kg = 1325kg
whats the power to weight of 1325kg meg then ?