After rummaging through my books I searched the net for information. The results were not of a gigantic magnitude. However here are the fruits of my labours:
"In the foreground 'Northern Horse' in mail charge the typical Irish cavalry." [Derrick print 1581] RA p42
To me the English are reminiscent of certain Late Roman cavalry with their mail and shields. The Irish have strange helmets (or helmet covers) more like Sassanids. I need to raid my 'spares' box.
"Carberry Hill - forces of the Scots Confederate Lords." RA p45
"Carberry Hill (1560's) - Mary Queen of Scots' troops." RA p46
The illustrations don't help much - the descriptions are as follows:
"A very small component of most Scots armies....the ordinary gentry would wear corselet, jack or brigantine, bascinet helmet, gorget, 'splints' for arms and upper legs, and mail hand and knee protection. Great nobles could have full plate armour....basic weapon would be the lance." [RA p45]
"The cavalry had helmets and sleeveless buff-coats (though jacks were also permitted) and were supposed to carry either pistols and broadsword, or light lance." [RA p45]
"The cavalry had helmets and sleeveless buff-coats (though jacks were also permitted) and were supposed to carry either pistols and broadsword, or light lance." [RA p45]
Osprey book - 'Border Reivers' - which I must acquire asap.
"Usually the chief mounted troops of Scots armies were 'Border Horse' armed with light lance, sword, and, by 1600, one pistol, with 'steel bonnet' - often covered by a cap - and corselet, mail or jack as protection: leather breeches and boots. They were distinguishable, if at all, from their English counterparts only by chequered plaids and the saltire of St Andrew on breast and back." [RA p45]
"The borderers who fought for their respective countries at Flodden were armed and equipped in a very similar way. the man shown here wears a jack of steel plates covered in red cloth, mail sleeves, long leather riding boots, and a fine sallet with an articulated neck piece. He is armed with a sword, an eight-foot lance, and a small hand-wound crossbow called a latch." [Flod p24]
Sources:
RA = "Renaissance Armies 1480-1650" by George Gush
Flod = "Flodden , The Anglo-Scottish War of 1513" by Charles Knightly
Flod = "Flodden , The Anglo-Scottish War of 1513" by Charles Knightly
It looks like my "Scurrers" can indeed be used as irregular light horse for Scots-English conflicts but not (sadly) for the Irish. After Vapnartak I will, hopefully, be in possession of the Osprey book and able to fill in more details.