Early this year, Gensou Suikoden IV's edition was changed from Original, like it had always been, to Shokai Seisanban. However, the serial is SLPM 65600. I have strong doubts that Shokai Seisanban is correct.

https://gamefaqs.gamespot.com/ps2/91888 … en-iv/data
https://www.play-asia.com/genso-suikoden-iv/13/7046a
https://www.play-asia.com/genso-suikode … /13/70239m
https://www.play-asia.com/genso-suikode … n/13/7093y
http://www.jp.playstation.com/software/ … 65599.html
http://www.jp.playstation.com/software/ … 65600.html

Even Playstation's own catalog listing confirms it. Read what it says in SLPM-65600:
クリアアートパッケージ仕様。裏面に書き下ろしイラストを使用したダブルジャケットになります。
Clear art package specification. It will be a double jacket using illustrations written down on the reverse side.

And from SLPM-65599:
プレミアムパッケージは、
「キャラクターイラスト&設定資料集」
「罰の紋章ルミナスキーホルダー」
クリアアートパッケージ仕様です。
Premium package,
"Character illustration & setting material collection"
"Emblem of punishment Luminous key holder"
It is a clear art package specification.

Both have the clear cases. Was this changed just because it came in a clear case? Or is there some very strong evidence that SLPM-65600 is actually the limited edition? 99.9% of the time the lower number of two serial numbers is the limited edition and this looks to be one of those cases...

Hi Egen! Sorry for the delay in getting back to you.

It was changed at the request of saolin, who redumped it and stated that it is the Shokai Seisanban edition of this disc. Saolin also said SLPM-65600 was in clear art package, when  verified SLPM-65600.

Also, as far as the serial id naming goes: 

SLPM 65599 (Genteiban) - Limited edition
SLPM 65600 (Shokai Seisanban) - 1st print edition
SLPM 65656 (Regular edition) - Regular edition

So the serials go in the correct order for these editions.

Also if you look at Konami's release of PS2 the Best release,  they don't typically use Genteiban or Shokai Seisanban's serial for PS2 the Best releases. The PS2 the Best edition (SLPM 74213) has been dumped already and it had internal serial number SLPM 65656.

As far as internet sources go:
https://www.suruga-ya.jp/product/detail/144002069001 - stated as Shokai Seisanban

https://www.suruga-ya.jp/product/detail/144002072001 - stated as regular edition

All being told, Konami made this one confusing release by not printing the edition anywhere. I can see why it could have been called Original edition previously.

Hope this helps!