I was surprised to find Fine Molds have several variants of the Type 97 Chi Ha. i bought 3 of the kits recently. FM21, FM26, FM27 for a reasonably low prices from Amazon.ca

As I cannot read Japanese, I hope others can shed a bit of light on the variants. I looked in my Osprey Japanese Armor booklet by S Zaloga and cannot find any too much detailed info.
I always thought the two Tamiya kits were representative of the the Chi Ha. I thought the new turret/gun combination brought along the new hull. I did not expect so much variation.

FM21 Type 97 Chi Ha Shin Hoto with late hull
FM25 Type 97 Chi Ha 57mm gun with late hull
FM25LIM Type 97 Chi Ha 57mm gun with early hull
FM26 Type 97 Chi Ha Shin Hoto early hull
FM27 Type 97 Chi Ha 57mm gun with additional armor (early hull)

Shin hoto turret with early hull. Were these a retro fit of the new 47mm gun turret on early hulls from service tanks or was it representative of a transition model on the production line (made entirely from a new tank)?

57mm gun turret with the new hull. This model seems like an odd combo. So was the new hull (meaning new engine?) produced before the 47mm gun shin hoto turrets became available? New hull to accommodate a new engine?

Type 97 Chi Ha with add on armor. Was this a field modification? What areas of Asia did it serve in? China or south Pacific islands?