Open up OpenIV and open up your latest update.rpf (1737).

Open up a new instance of OpenIV and open your previous unmodded update.rpf (1604).

Compare all file sizes.

If that is too much work, I can only say that you should have kept a record of some sort when modding your rpf. Every mod I download and install, I update their readme.txt with any info I changed along the way. I also move mods I used to a separate folder from the mods I downloaded but did not use (e.g. path\to\downloaded\mods\unused VS. path\to\downloaded\mods\used). It helps me keep track of which mods I have currently installed and which ones I do not. All readmes contain which files went were and what changes if any.

My only suggestion, so far. Maybe someone else knows a better way.

Your slashes "\" are backwards for your mods. They need to be the other direction "/". The same as official dlc shows on the lines.

I would like to know if someone can convert the Spatula of Doom vehicle. I absolutely loved that mod in GTA:SA and would really love for it to be in GTAV. If not possible to convert due to being unable to attain permissions or even the model itself, might someone be skilled enough to create a GTAV version (with proper respect to original owner and not being an actual replica, of course) of it, that would work, too. That mod was so fun in GTA:SA, I think the fun needs to be updated to recent San Andreas. Thanks to whoever is interested in taking up this request or to whoever provides the info as to why it can not be done.

EDIT:
Link to original GTAForums post.

I have a small suggestion that deals with the log files from mods along with scripthookv and scripthookvdotnet. I understand SHV and SHVDN are not really from this site, but they are posted and maybe they can get an ear of this, also. My suggestion is, due to my GTAV folder getting littered with log files from asi/dll mods, (if doable, in the first place) that creators can possibly program their asi/dll files to create their log files in a "logs" subfolder in GTAV. This isn't really a over the top serious issue, but my folder now has about 8 log files from various mods plus SHV/SHVDN. It just looks cluttered, now, especially since some have a date appended to them, as well. Like I said, it is not an extremely serious issue, but merely an aesthetic annoyance to have all the logs in the root folder. The only issue would be that maybe some authors could/would do this from now on, but others might not, therefore leaving half the logs in root folder and the rest in a subfolder. Which would just be a slightly smaller mess. ...or maybe an asi or lua that can move logs in root directory after you exit the game to a subfolder. I can even go further away from it by just creating a bat file, huh? LOL. I can only speak for myself, though. Just something to think about, modders.

I had this problem for a short while, some time ago. The way I "fixed" it was by not using a mods folder at all. I moved copies of original game files to a separate subfolder and placed all my modded files in original locations. As long as you keep the 'OpenIV.asi' file in the root directory, it should load up all your mods. I even created a .bat file to swap files around depending on whether it is modded or not. This all started for me some time ago with version 944.1, I think. Every update I try to check if it works normally for me with a mods folder but it always crashed on startup (update.rpf error). I just left it at this method because it just works for me. I am not saying it will definitely work for you, but it's a thought.

Do script conversions count? I liked the Master Spark script mod for GTA:SA by Ryosuke. If you are willing and are able to, may you convert it to GTAV, please? I had so much fun with it in SA. Big thanks for even asking if people have ideas for mods!