Slovakia "Slovokia" (post-?) World War I unknown uniform

[Mark C]

A query arose on a genealogical site regarding the indentification of these men. They are brothers from Holic in "Slovokia," said to be World War I. The uniforms are Austro-Hungarian, but the insignia are unfamiliar. Could they be early post-war Czech? What are the cap badges? The collar numbers are "4" for the man on the left and "301" (!) for the one on the right.

http://gmic.co.uk/uploads/monthly_07_2012/post-4974-0-71054100-1342616077.jpghttp://gmic.co.uk/uploads/monthly_07_2012/post-4974-0-90324400-1342616089.jpghttp://gmic.co.uk/uploads/monthly_07_2012/post-4974-0-23794100-1342616101.jpghttp://gmic.co.uk/uploads/monthly_07_2012/post-4974-0-54982500-1342616212.jpghttp://gmic.co.uk/uploads/monthly_07_2012/post-4974-0-10054500-1342616453.jpg

[Iver]

Hi... these are czechoslovak soldiers, cca 1919-1920. Cap badges are with letters RČS which means "Republika ČeskoSlovenská - Czechoslovak Republic (letter R on the top, Č and S under and on sides) used cca 1918-1920, caps are in new form (inspired by French uniforms) used after 1919 and with badges of rank on the sleeve. the number on the collars are numbers of regiments....