Just a few notes to help you navigate Baugher's site.
He has USAF
which includes US Army and he has Navy. Select the one you want.
Navy uses Bureau Numbers (BuNo) which are sequential starting way back. Easy to search.
The displayed tail number is most often five digits. The first digit is normally the last digit of the fiscal year, within a decade, that the aircraft was acquired by the service. The next four digits are just the sequence, within a block of numbers assigned to an aircraft acquisition contract. So to use your first example:
That 7 means we could search 1947, 1957, 1967, 1977, 1987, and so on. Best bet is probably 1957 as the -135 was a brand new aircraft back then. Sure enough Baugher's sources say that the sequence 1418 through 1514 were Boeing KC
-135A-BN Stratotankers. Some times he even has additional info about a particular airframe. In this case he has notes on 71490 and 71497 but nothing on the one you enquired about.
This one suggests a search in 1960/'70/'80. 1960 the last four numbers would make it a Martin Bullpup missile. If you are fairly sure that is not what you were looking at, let's try 1970. Nope, in that year the USAF
numbers ended at 02523 and the Army numbers start at 70-15000 which was a CH
-47, a Charlie model. Impressive aircraft but easy to distinguish from a T-38. How about 1980? Nope, no numbers in that sequence at all. Likewise in 1990. 2000 as a remanufacture of some kind? No.
So I'm stumped.
There is an Army regulation that says if an aircraft is more than a decade old a zero can be added to the beginning of the tail number to distinguish it from any number conflict. Don't know if the Air Force uses that protocol but it could be. I am going to run out of time here but you could start that kind of a search. Find a year in which the USAF
was acquiring T-38s and search for the 1494 and even for _494. I have made a fairly thorough search over the period from 1959 through 1971 and not found anything that might be it. So, two suggestions.
1. Be very sure you have written the number down correctly.
2. Look carefully at the lists of all blocks of T-38 aircraft. There are only a limited number of years in which they were buying these aircraft.
If the aircraft in question is a 'display' aircraft, on a plinth or on a stick, then the number displayed might be bogus.
Finding the c/n from this information, I cannot help you but someone here probably can.
Happiness is not seeing another trite Ste. Maarten photo all week long.