I dug out my old ref list for determining who-made-what. Maybe it will help.
Mayflower 1/50 (actual: 1/64) Revell kit 5602 20” simplified build (19” on box, sometimes listed as 24” ie: kit #H366)
Mayflower 1/60 Trumpeter (Said to be same/similar as IMAI 1/70 kit as many parts look alike) ( Some parts appear Out Of Scale according to one review.)
Mayflower 1/70 IMAI, ERTL (depicts year 1615) (Beautiful kit.)
Mayflower 1/83,(actual: 1/96) Revell 14-3/4" H316 (appears same as Heller 1/150 kit) ie kits: #05486, listed as 16”, #H327 listed as 13” H316 (Mold used for other Revell kits)
Mayflower 1/96 Airfix, MPC. 12.6” ( Slightly larger than Revell- but very similar.)
Mayflower 1/100 Modelist (Probably Heller 1/150 copy. )
Mayflower 1/150 Heller Said to be a larger scale like 1/96. Heller deck looks same as Revell 1/83 kit.
Mayflower 1/250 (closer to 1/280) Pyro, Life-like, Lindberg (Differs from Mayflower II) (This kit was remade from Pyro orig Mayflower II-which was a wide hull/toy. )
Mayflower II 1/250 Pyro original (issued 1956, w/Wood masts, Wide hull- bathtub toy)
Mayflower 1/600? Gowland&Gowland (Old kit. Some Gowland kits issued bty Revell)
Mayflower 1/? Airfix small model (Appears same size as Gowland but with lower hull.
Nino