I suppose you could swap out the outside lights for modern H4's and eliminate the inner lights. Giving something of a cross between the 69 and 70 in looks. This is similar to what I did on the drag car but I don't run a stock type grill in it as its a one piece front end (not Shelby like, but I guess in that spirit). But, I too , am partial to the 69 headlight look.
69 351 TKO Sport Roof, Ride Tech coilover
70 557 PG Mach I tube chassis 2650lb
70 427 TKO Sport Roof, SoT full chassis to be
67 347 TKO Coupe SoT/CAT5
67 289 C4 Coupe stockish cruiser
69 460 TKO Vert, Mustang Plus Grab a Track
94 351 TKO AIX, Maximum Motorsports
02 3.6TT GT2 Porsche One lap America, JRZ,997 Cup suspension
Since I was a youngster, I had always wanted a 70 Fastback. That was, until I saw my first 69 back in 1998. While looking for a nice classic Mustang, I came across the car I now have. That four-eyed look, plus the fake side scoops and the taillight panel just caught and kept me.
One thing I have considered is moving the two inner lights closer together. This would require fabrication skills beyond mine. Something like the 2005-2009 Mustangs can have.