I reported that Bootsy was accepting Lucky and that I had Lucky-proofed the terrace. I wasn't all wrong. Last night I let Lucky out onto the terrace (it was raining). Then Bootsy went out and Lucky jumped up onto the then slippery 4 1/4 " ledge behind the A/C in the corner. I got Lucky back inside immediately. I hadn't thought Lucky would jump up onto the roaring air conditioner, but apparently it wasn't roaring at the time (or maybe it was). At any rate, if Lucky would have fallen off the ledge, he would have landed in the top of an oleander tree.
Then this morning, shortly after I'd gotten up, Bootsy attacked Lucky in my bathroom (mostly a vocal confrontation, as far as I can tell). I think Bootsy did it for my consumption (not appreciated, but he didn't seem to care). (I leave the bedroom door open all night long and have yet to be awakened by a confrontation.)
The rest of today went well, however. I even left the cats alone together while I went to pick up my Chinese food down the street. Lucky does have the advantage of being able to jump up onto surfaces that Bootsy can't jump up onto. I just want Lucky to be totally familiar with the apartment and know all the escape routes before I leave him and Bootsy alone together.
UPDATE (7/25): My bathroom has been kind of a "flash point" of confrontation, and now I think I know why. Originally, I had two litter boxes in a hall closet. When Lucky came, I put one of those in my bathroom for when I shut Lucky up while I was gone. Bootsy had used both of them, however--basically, one for #1 and other for #2. But when I took one of them away and gave it to Lucky (figuring Bootsy would adjust and use the one box), Bootsy got stressed. So tonight I bought a third litter box and put it in the closet, so Bootsy has his two again.