Modifications for scenarios

[Chaplain Bear]

Aim, since if you recognise the name from the old lobby or the clan.
I aim tio rebuild scenarios for multiplayer purposes and single player purposes. Who here remains that can provide information on modding?
I, like many others probably think the watchman model and texture looks "naff", how many of you can help me with the dilemna currently having where I am trying to swap out the model of watchmen
gun_sentinel_15.cem
Using EE studios, I have extracted both, the above and the guardian model - men_lasertrooper_11.cem
, decompressed the above, renamed it gun_sentinel_15.cem, placed in the model folder in EEAoC data.
Have also created a Master Chief texture, and added to the textures folder gun_sentinel_15t.tga

So it would go, sentinel, guardians, and finally watchmen in the form of Master Chief (note will be editing this as well in the language folder so they become known as Spartans in gameplay, as well as through triggers in scenarios)

However, from my recollection of the last time I did this, I believe I must have missed a step. This should swap out the models, with Watchmen model changing from crappy robot soldier, to a taller guardian model, and thus green, coming across as the idea of a giant super soldier. However what I have instead is invisible watchmen who's movement cause the screen to blink in and out.

Having tried the same modification on 3 computers, have come to the realisation it must be a missing step and not computer hardware problem.

Any help available? Question has also been asked in EE Heaven, so one way or another, maybe 2 ommunities can provide an answer