I give up. I have searched here and elsewhere for a solution that works for me but nothing does. I am running a custom TW ROM (Dandroid 3.9 for JB 4.1.2) on Verizon firmware VRBMF1, so the fix for JPX/JPY firmware won't work for me. Other mods I have seen are for different firmwares also, and Wanam Xposed only works from JB 4.2+. I have also tried 3rd party apps that supposedly fix this, but SMS Sent Time Fix does not work, and SMS Sent Time does not actually fix the timestamp on the message; it only appends the actual sent time to the end of the body of the message which I don't prefer.
I did find a modded SecMms.apk with a fix baked in which does successfully add the actual sent time to the 'date_sent' field in the mmssms.db database; however this still does not accomplish the task of substituting the time sent in the timestamp that appears above each message. Also knowing that the SMS Sent Time app can locate the actual date/time sent gives me the belief that there has to be a way to get the timestamp in my conversations to use this value. Technically it wouldn't be the time I received it, but in cases where I'm in airplane mode for hours - as happens frequently - seeing that I received a text while my phone was off and knowing the time it was sent is more important that using a true time of receipt.
If I thought it was a limitation with JB 4.1.2 I would bite the bullet and update either to 4.3 or even to KitKat, but I like to think that it's possible yet the developers that do all this amazing work haven't found that Verizon SCH-i535 phone running TouchWiz Jellybean 4.1.2 to test on.
So does anyone have any ideas as to what I can try next?