The new (internal bag lid) attachment points for cables obviously came on the 99 Interstates, but I am not sure if 99 Tourers got those lids the same year, or the next in 2000 (this is true of a number of part changes made with the 99 (first year) interstates, that later got added to Standards and Tourers).
Careful comparison study of part numbers (for lids) on 99 interstates and 99 Tourers may answer the question, but don't get hung up on differences based on paint color. (only compare black to black part numbers, the only paint color that is used on both interstates and tourers)
Note that the 99 interstate bag lids not only got cable attachments, but rubber tipped standoffs (which also had new internal attachment points), so when the bags were unclipped in front (instead of the permanently connected Tourer hinges) they did not lay on the paint of the saddlebags. These standoffs do not have to be used if you are careful not to bang them on the bag paint, and if you happen to have the (OE or aftermarket) bag rails, cable connected bag lids cannot touch the paint, but just lay on the rails. I took the standoffs off both my interstates bag lids because both have bag rails, and removing the standoffs makes it easier to cram the bags completely full of stuff, and still get the lids snapped down on them (the standoffs interfere with that).
The parts schematics for 99 interstate bags and lids (with cables, screws, and clips and standoffs) is one of the hardest to follow with all the tiny parts needed for the complete assembly. And assembling a list of all the tiny parts needed is a challenge (times 2 or 4 of each).
Here you go.
https://www.procaliber.com/oem-parts?aribrand=HOM&arian=MOTORCYCLE#/Honda_Powersports/GL1500CFA_(99)_VALKYRIE_INTERSTATE%2c_USA%2c_VIN%23_1HFSC410-XA000001/SADDLEBAG/61347acc-638e-40e4-aa4f-0fceb839ab88/34557c9a-e4ac-4516-a4eb-207841eaa5d4/yNow here's the deal... If you find that your 99 Tourer lids do not have all the internal attachment points necessary for 99 interstate cable tied lids (you need cables, but not the standoffs), it is still possible for you to cobble together a cable system that will work for you. You still need to replace the Tourer front hinges with interstate front mount clips (which will mount up on all model years), but instead of using the OE cables and clips (to mount points you don't have), you can fabricate (somewhat) longer cables that attach to the screws used to mount the front clips and rear latches (wrapping thin wires around the screw heads, like electrical work).
I don't think the interstate lids are still available new, but new or used, they get very expensive to buy (and maybe paint), just to gain the internal lid cable attachment points.
And you can just replace the front hinge with the interstate clip attachment and use no cables at all, but I'm here to tell you that you can have a lid fly off the bike after hitting a bump hard enough to jar that front clip loose.
I did away with the cables on one interstate for a while, and once the front clip got jarred off, the wind got under the lid and it flew away like a sailboat, and one lid got run over by a thoughtful driver behind me. And replacing that lid (used, with body shop repair and paint), and new hardware, and a single OE Honda bag rack (to match the other side), cost me upwards of $600. You must at least run one front cable to stop a lid from flying away on you, though only that single cable will allow the lid to flop all the way over the side of the bag when loading and unloading.

A real Rubik's Cube (the 99 interstate was rushed to market, and this is not one of the more user friendly setups Honda ever came up with)
And it's real difficult to even find any good pictures of the inside of an interstate bag lid to look at the new attachment points.
Rather than a hard trunk, you may find a big (waterproof) soft-side duffel bag will allow you to keep your Tourer hinges (and your sanity, in the cable tie conversion).
PS: I've posted on this subject in the past, and it's possible I did a parts list years ago, but I don't have much luck researching old posts on here.