HGE = Heavy Gold Electroplate, used as an accent on almost all $20, $40 and $200 silver strikes.
HSP = Heavy Silver Plate, used on many of the later cruise ship strikes.
$2 strikes were issued from nickel machines. Aladdin, Harrah's Reno and Edgewater in Nevada. Teller House, Colorado Central Station and generic (from several casinos, but bearing no specific casino logo) from Colorado. Grand Casino (Biloxi, but ithey don't say Biloxi) in Mississippi. Many different generic sets were issued in South Dakota. The last $2 strikes were motorcycles from South Dakota in 2000.
Final piece of boring strike history is the Horseshoe strike depicted was in play from approximately 1994 through 2000. There was a Millennium $40 from the Horseshoe which was never in play although many were sold from the cage.