The Marchers were mostly dressed with laced gambesons over basic laced shirts in various combinations. The Shoddy Knight is only a gambeson with only one inside out sleeve laced on (thus contrasting with the main body of the gambeson). The grey gambeson is also worn with one sleeve. The Valkyrie, breaking this trend of asymmetry, is in a dark blue gambeson with both its sleeves.
The Proprietor and the Pillywiggen are both actually dressed in Tudor reenactment kit. The heat and the wool did not mix very well.
The laced gambesons are available from Character Kit for £60 each. The shield and polearms (pike and halberd) also available on Character Kit, the latter at the discounted cost of £75. The scythe is from Wandering Soldier.
More photos of the Marcher Rabble under the cut.