Ray,HarryCox was recordedin 1956,singing German Musicianer by PeterKennedy,this is the most likely source ,as I am very sure I heard PeterBellamy sing it,before Walter was discovered.
Peter kennedy also collected the greasy cook or butter and cheese and all[not sure which variant]in 1953.I reckon he[Peter B] got them from HarryCox.
PeterBellamy it also was, who brought peoples attention to Walter[I think before anyone else was aware of him as a singer]
Jim , you have to thank a revival singer,ForHaving discovered Walter.