If you can climb inside the trunk. You can release the latch from the inside. I had to do that with my 74 Maverick when I bought it because I didn't have keys either.
I repin my own locks. My Comet had mismatched keys, I repined Ign & both doors to a pair of NOS keys from the '60s. Were originally pinned to in dash ign switch but never used. Trunk only had one key, used two key lock set orginally from a '69 Torino.
If you have a locking glove box, you can get the code from the lock cylinder and have a key cut from the code.
I don't know if that always works. I've never seen a glove box lock with more than three pins, in theory multiple keys can operate it, but not trunk lock that has five. Wanna have fun?? Try repining '85-up locks with 10 pins. Actually, those have flat discs instead of pins. I once called a lock smith to cut a key for one of those, said he couldn't do it. Funny I had one cut by locksmith at a auction, many cars with no keys.
