There are two things that you must look at on a 1986 vert with a removable hard top. First, is the hardtop an OEM or an aftermarket hardtop. If aftermarket, then, from what I have heard, there are no attachments for the pillar locations. If OEM, you should be aware that the hardtop was not an option for 1986 verts. However, GM did make an adapter kit for the 1986 vert that would allow for the hardtop to be attached, especially on the pillars. This adapter kit is no longer available from GM to my knowledge, and they are extremely hard to find on the internet sources. I did see one advertised on one of the forums (don't remember which one) several years ago.
You are correct on the attachment on the pillar, there are L shaped brackets that attach to the frame behind both seats with bolts. The hardtop slides into the bracket and is attached to the bracket with bolts. The brackets are hard to located by themselves also, and the bolts cost about $7 each.
I doubt that the hardtop came with your vert, since it wasn't an option. Therefore, the hardtop was probably purchased used by a previous owner. Since you do not have the L brackets, the hardtop will not be as secure as when you do have them. You should note that the bolt attachment on the rear deck require that the bolts be tightened with a wrench, they do not just slip in as the convertible top does.
Hope this helps. You can search the CAC forum on this subject as I have responded to several threads on this subject. BTW, I have had hard tops for my 56, 66, 91 and 94 verts and love them.
Barrett