Sir-
-Diagnostic Output was copy/pasted from serial monitor. Will place in code window next time. 
-display 800×480, 7.5inch E-Ink raw display
-Hat Universal e-Paper Raw Panel Driver HAT
HAT -> MKR1000
Busy -> 5
RST -> 6
DC -> 7
CS -> 4
CLK -> 9 SCK
DIN -> 8 MOSI
GND -> GND
VCC -> VCC (confirmed 3.3V)
I'm using the suggested mappings from GxEPD2_wiring_examples.h
// mapping suggestion for Arduino MKR1000 or MKRZERO
// note: can't use SS on MKR1000: is defined as 24, should be 4
// BUSY -> 5, RST -> 6, DC -> 7, CS-> 4, CLK -> 9, DIN -> 8
This configuration also matches the constructor in GxEPD2_display_selection_new_style.h
//lines 194 and 195 from GxEPD2_display_selection_new_style.h
// adapt the constructor parameters to your wiring
GxEPD2_DISPLAY_CLASS<GxEPD2_DRIVER_CLASS, MAX_HEIGHT(GxEPD2_DRIVER_CLASS)> display(GxEPD2_DRIVER_CLASS(/*CS=4*/ 4, /*DC=*/ 7, /*RST=*/ 6, /*BUSY=*/ 5));
Noted: Waveshare wiring differs from ZinggJM wiring - i like yours better.
I must have the wrong panel??