To copy the individual files you've downloaded to the main memory you firstly need to know what's in there now and you also need to know how your current GarminDevice.xml compares to the one you used to download the maps, that's because if the XML now being generated by the unit is missing the unlock codes then the locked map may not work. If it has no registration or unlock codes in it you may as well just use unlocked maps on a card. Look for the codes right after '</id>'. This is mine disguised:
Baby steps: First let's dump the internal file system which is contained in region 48, and we'll get the current region 41 too for safety. Use a clean microSD, minimum size 4GB. In a Garmin root folder place sub-folder Updater. In Updater folder place one named 0972 [or if yours is MTK chip with HWID 1104 use that as the folder name]. In the 0972 or 1104 folder place Ldr.bin [it's just your boot.bin renamed, get it from the firmware using RGN_Tool]. Also in that folder place a text file named Update.txt with the following command:
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You can copy/paste the above or write it yourself into a txt file using Notepad, but either way be certain there are no spaces before or after or extra carriage returns. Make sure you use the CORRECT firmware to get boot/Ldr.bin from because if you get it wrong your device will be dead forever if it's also without preboot available to connect to PC as it is with Mass Storage Mode.
Place the card in the device with it off, plug it into a power source to turn it on and wait. It will take some time to dump rgn48 as it takes up much of the 2GB total size available for flash regions in 1xxx even if there's much less data actually in it than will fit [as it dumps free space too, so it'll be ~1.8GB]. When you have 48_backup.bin in the root of the card, open it in a suitable program. I use PowerISO:
The above is showing the .System folder contents from an initial rgn48 dump of my 1490 a couple of years ago. Once you know what's in all folders you know what to delete so that you don't have conflicting or unnecessary files onboard with your new files. Probably not only Lane Assist function but also maybe JunctionView and even the Speed Limit Indicator may not work either. I hope you haven't lost TTS but i don't think so. Do a simulated route to see what works and if JCV does or doesn't work with your present map, 'cos if it doesn't there's not much point transferring the files.
PS: I hope you are absolutely sure that the XML you used is for the same unit, if the Serial Number on the base of your 1490 and that shown in GE above match it's safe to use. BTW, for safety and anonymity never post your S/No or Unit Identification Number [UID] in open forum as zakon kindly advised you. I've disguised it in your first image.