I think you're right. I remember seeing one set of oem brake controls that had a u-bolt type of clamp that looked like it went around the frame rail. How about the reservoir? I keep reading "between the down tubes". I'm not ashamed to say that I don't know what downtube they are talking about. One old thread someone posted that they had to move the MC or reservoir to install an oil cooler. One reply mentioned the MC being mounted to behind the regulator.
I saw a set of floorboard controls on the bay and that sent me down another rabbit hole.
I also found a set of kick back plates that move the controls back a little but I'm afraid the left controls are already too close to the primary and the right are too close to the pot luck exhaust they have on there. Besides, these controls I have on this bike is flimsy. the brake pedal is too far from the peg, the shifter and linkage are very sloppy. I think i matched the set up to a $200 V-factor kit but worse. It looks like they may have cut and welded the toe shifter to make it longer. I made some adjustments to the handlebars and went out for a test ride and the shifter to linkage clevis pin fell out. of course i couldn't find it but got lucky and found an old zip tie and made it home. You get what you pay for but if I'm going to pay I'd rather have OEM controls. Maybe even floorboards.
I was talking to my indi and was telling him what i was looking for and I mentioned how great the parts fiche was. He told me Harley offers it now. You just how to log in and look under parts. It has a little more info than Ronnie's. Yesterday I was looking for 1989 - 1993 softails and some years only list Sportys for some reason.