I am sure that you already know about Rob Crowe's excellent unofficial OFA remote website
www.hifi-reemote.com It has an explanation of how to test for all commands under a setup code (that I assume in your case is DVD_0490).
There are 256 total commands for DVD_0490 and probably the only way that you will find the commands that you are seeking if they exist.
The other alternative is using ccf2efc (found in the Pronto download section under utilities here at remote central) and decoding ccf files for the Panasonic DVD's that have a prefix of RP where the P would seem to designate a progressive scan player found at
[Link: remotecentral.com] Neither of the models that you cited have files posted and ccf2efc will only work for those files that under "Remote:" have a (P1) suffix. I have listed the commands that I found for an RP-91 posted by Arthur Legardo
EFC=Advanced Code
OBC=True Command code in decimal
All are Panasonic protocol, device =176
OBC EFC
000 181 stop
001 185 open close
004 180 rewind
005 184 ff
006 182 pause
010 055 play
016 117 1
017 121 2
018 119 3
019 123 4
020 116 5
021 120 6
022 118 7
023 122 8
024 245 9
025 249 0
051 155 audio
061 024 power
062 022 on
063 026 off
069 168 hpvss
072 037 a-b repeat
073 041 back
074 039 forward
128 189 menu
129 193 return
130 191 enter
131 195 cancel
133 192 up
134 190 down
135 194 left
136 061 right
137 065 10
140 060 repeat
141 064 play mode
142 062 marker
144 125 angle
145 129 subtitle
146 127 display
148 124 action
155 003 top menu
158 254 spvss
224 205 group
225 209 audio only
229 208 page
232 077 text
Jon