You have my curiosity now.......If it's an 86 production, as far as I know, Leo was the only one that had these guns during that time period. Etchen had a run made I'm guessing......late 90's, 2000-01....sometime after Leos..... I have a NIB Leos Gr. 6 Pigeon (34" fixed full, straight stock) that's identical except it's blued and numbered....made in 87. I live only about 25 miles from where Leos was located and got to know him pretty well. I was fortunate to see about 50 or so (Gr.1's and Gr. 6's) of his BT's lined up in the shop......an got a tour of "the back room".....what a sight that was.....anyhow, I never saw one of his BT's that was not numbered in gold above the lever so I'll be real interested in hearing what Browning tells you.
I purchased two Leo Special BT-99's in 1995. One was a Grade 1 (w/G3 Wood) MC Comb 34" Barrel while the other was a Grade 6 Gold on Blue Straight Comb 32" Barrel (Only G6 in inventory at that time). My BT's had the later Invector + ported barrels. Both had the wide Beavertail Forends which are unlike the BT in the photo.
I sold the G6 six years ago but have kept the G1 and shoot it a couple of times a year for old times sake.