This comes up every so often..
Due to Grandfather Laws that apply in all states (I assume you mean the US?), if the vehicle has all safety gear present When manufactured; it is street and hiway legal in 2019.
It needs registration, a license, yes.Your Ford came with tail lights, all did. (Just not Brake lights until maybe 1917.) Some were oil lamps. I suggest you replace them. All Ford taillights were reflectors, too. Even Amish buggies need rear reflectors. Adding mirrors is an excellent idea, although not required. Clamp 'em on, don't drill holes.
We have a gaggle of Model "T"s, A's, Auburns on our freeway going to the Dillinger Days, downtown, in Feb. Safest to be in a group in R lane with those triangle reflectors, but law says they don't have to do that. Most regular drivers of Ford "T" 's "electrify" them. Battery, starter, generator, electric lights.(not those who show them where they have to be 100% authentic.) I've seen 1910 "T"'s with electric headlamps.
"Hiway speeds"? I've seen trucks with trailers legally limited to 55 on a 75 MPH freeway. You can go as slow as you Want. In fact, it's illegal to try to do posted speed, if your vehicle and conditions unsafe to do so. My '86 Toy, I dont push over 65. Modern motorcycles are freeway legal with 15 GBHp (or 125 cc, now) or better. Model "T"s are 20 Hp. Not that a "T" or a 125 is Recommended on I-10, but law sez, Legal.
REF: Know a lot in old car clubs.They all agree on this for ALL states. Some of my family is from Mennonite town in KS, lotsa buggy traffic. If the lies about a old cars on the street were true; they'd need safety glass, 4 wheel brakes, signals. mirrors, as well as electric lamps, brake lites, and a turbo to get over 45...all Rubbish. My daddy grew up driving "T''s, he showed me how to start /drive one, scrape bearings,tickle coils, etc..