OK, my 50+ year "engine collection" that I have two or more of (haven't counted lately) is as follows:
McCoy Super Stunt: .29
McCoy Red Head: .19, .29, .35, .40
Merco Red Head: .35
Veco/Allyn: .35
Veco: .19PB, .19BB, .29, .35, .45, .50
K&B Green Head: .09, .15, .19, .29, .35, .45
OS: .10S, .10FSR, .10FP, .15FP, .15LA, .20FP, .25FP, .25LA, .40FP, .46LA, .30S, .35S, .40VF
Super Tigre: .35C, .35CS, G21 .40, G21 .46, G-.51 (new version), V.60
Thunder Tiger: .36
Aero Tiger: .36
PA .40, .51, .61
HP Gold Cup: .40
HP SS: .40
Johnson: .35, SS
Fox: .15 Rocket, (early) .19, ('57).25, .29, .35, "Big case '70s" .40 Stunt
Fox: "Sandcast" .35
Magnum: .36XLS
Webra: .28, .32
Double Star: Classic .40
Brodak: .40
Cox: Pee Wee .020, Babe Bee .049, Golden Bee .049, Black Widow .049, Killer Bee .049
Anderson Spitfire: Ignition .60, .65
Super Cyclone: Ignition .60
I have many singles of others....
BIG Bear
RNMM/AMM