JR, your special order number dates you M24 to July 4, 1984. The product code is for a pretty much standard production 3-inch M24, which normally would suggest the engraving was done after it left S&W, probably by the distributor. Otherwise, it would of had a more unique pc. Lew Horton sold some, I don't know if all of the 100787's , and I have notes that 5,000 were made. Enough that I have nine in my s/n collection (not counting yours). None of these were engraved, though at least some had Combat Stocks. The following s/n's have that pc. It's interesting to note that some of these shipped in the old style two-piece box. But instead of a hand written label, which was the norm for those boxes, they had the new style computer printed end label. An uncommon practice. That's all I got.
AEJ82XX ……… June 26, 1984 (M24-3 3") RB RR WO CS LH 100787 2pc-nbc 4177
AEM10XX ……… July 7, 1984 (M24 3" 44S) RB RR WO 100787 2pc-nbc 4188
AEM11XX ……… June 26, 1984 (M24-3 3" 44S) RB CS RR 100787 2pc-nbc 4177
AEM77XX ……… July 7, 1984 (M24-3 3" 44S) RB CS WO 100787 2pc-nbc 4188
AEM80XX ……… June 1984 (M24-3 3" 44S) RB CS RR LH (5000) 100787
AEM81XX ……… June 27, 1984 (M24-3 3" 44S) RB CS RR WO LH 100787 2pc 4178
ALA22XX ……… Aug 30, 1985 (M24-3 3" 44S) RB CS RR 100787 1pc-n 5242
ALA25XX ……… Aug 30, 1985 (M24-3 3" 44S) RR WO RB CS 100787 1pc-n 5242
ALA48XX ……… July 24, 1984 (M24-3 3" 44S) RB 100787 2pc-nbc 4205