Hi SAS~Bombsaway,
I hope that everything is fine with Riken, it's a pity he is not here with us, he always had a lots of interesting ideas.
Upgrades would be very welcome especially landing lights and a few other things you mentioned.
I came across a few mentions that the Mitchel B-25C / D aircraft used such weapons as Hvar rockets, glide bombs (PBJ1 aircraft were also used to test BAT missiles), and aerial mines, but I did not find much about PBJ1.
http://www.microworks.net/pacific/aviation/pbj_mitchell.htmI assume that the Navy PBJ1 aircraft had similar armaments, especially their counterparts of the B-25C / D types.
unfortunately, it's hard for me to find up a solid source.

The USMC received the following aircraft:
PBJ-1C: 50 aircraft: 25 B-25C-20-NAs and 25 B-25C-25-NAs.
PBJ-1D: 152 aircraft: 25 B-25D-15-NCs; 49 B-25D-25-NCs; 61 B-25D-30-NCs; and 17 B-25D-35-NCs
PBJ-1G: 1 B-25G-5-NA
PBJ-1H: 248 aircraft: 52 B-25H-5-NAs and 196 B-25H-10-NAs
PBJ-1J: 255 aircraft: 14 B-25J-1-NCs; 7 B-25J-5-NCs; 7 B-25J-10-NCs; 20 B-25J-15-NCs; 84 B-25J-20-NCs; 47 B-25J-25-NCs; and 76 B-25J-30-NCs.
loading min on PBJ-1 (10:48):
Bombs for PBJ-1H Mitchell:
12 x 100 lb AN-M30A1 bombs
8 x 250 lb AN-M57 bombs
4 x 500 lb AN-M64A1 bombs
unfortunately not too much of this information.

Best regards,
Piotrek