I don't have a book of P1Y1, but ja-wikipedia maybe reliable only about loadouts.
Top gunner: 1x 20mm
Rear gunner: 1x 20mm
Loadouts:
- 1x Type91 torpedo or 1x Type91-Mod7 torpedo
- 1x 800kg bomb
- 2x 500kg bomb
- 2x 250kg bomb
Optional:
- 2x 600 litter drop tanks as one under each wings
(P1Y1 could not carry many smaller bombs.
Japanese remote control rockets "I-go" series are developed only by Army and planned as only carried by IJA's Ki-67.
MXY-7 "Ohka" 's subtype-22 was tried to develop for P1Y1, but not finished and never carried by P1Y1. MXY-7-22 was much different shape and engine, flight characteristics from MXY-7-11 existing in stock game.)
Its bomb bay doors were separated into 4x leafs like D4Y.
2x were folded to left side and other 2x were folded to right side.
D4Y was modeled by ten010 for IL-2 1946, but his bomb bay door was incorrect (only 2x leafs it has).
About the books written in Japanese , this is said as the best one, today.
ISBN: 978-4893190819
Price: 2594 JPY ...... so about $25 or 22.4EUR
https://www.amazon.co.jp/dp/4893190814/Published in Sep./2000 with newer data and considerations.
But I don't have it and impossible to buy it soon (I've bought too many books about modern Jets these days.)