Ok, In my idleness, I went and looked up some old catalogs:
1993, 1994, 1995; Show No Mark X's at all... Thus I would guess that was when that area of Europe was in the midst of wars. Likely not exporting any sporting rifles at all...
The newest catalog that shows any Mark X rifles was my 1989 and it shows only the Lwt (With Butler Creek stock) the Viscount, and the "American Field" models,
NO Mannlichers !
My 1987 is the only catalog I have that shows Mannlicher stocked rifles. These are only "Whitworth" rifles. (Catalogued in five calibers: .243, .308, .270, 7x57, and .30-06) The Mannnlicher-styled Carbine is shown with Std Mark X bolt handle, inside the bow flr-plate release, and single trigger. The buttstock is shown with a straight Classic-Styled comb!
Not a Monte Carlo! I have never seen one before, and never knew they existed.
Thus I would deduce that the other two models mentioned previously came prior to 1987... Sorry folks, that's the best I can do...
Grasshopper
P.S: Here is a link to one I recently sold:
http://www.auctionarms.com/search/displayitem.cfm?itemnum=9210387