Making an Adjustable Bridge For a Flattop Acoustic Guitar

Friends asked me to work on a Yamaha acoustic with chronic intonation problems. Basically, the guitar could not be tuned. After warning them that I really didn't know what I was doing I took the job.

The guitar's action was fine. The neck did not appear to be warped or bowed. According to my measurements the guitar has a 24 7/8" scale. Rather, it should, based on the distance from the nut to the 121th fret. The bridge and saddle were just a little too far away.
I decided that whatever the final solution was I wanted the current saddle off of the guitar. I used a heat gun and two putty knives to carefully remove the saddle.

I have a Yamaha acoustic of my own that was a gift from another friend. It has a bridge I have never seen on any other acoustic guitar.

It looks somewhat like a Gibson Tune-O-Matic, but the important thing, to me, is that is allows the type of intonation adjustment we are accustomed to on electric guitars. I want to give this treatment to the Yamaha given to me to repair. Among other things, it will give me leeway in replacing the saddle.

As I only caused minimal damage to the removed saddle I am going to modify it to accommodate a Gibson style electric bridge I have on hand.
I have started chiseling the edge of the saddle that faces the sound hole. I believe placing the bridge there will allow me to put the saddle back in its original location, correctly locate the bridge and allow access to the intonation screws on the bridge. I'll let you know how it goes.