All three gauges.

The first one I made was the standard marking gauge.

This one is a slitting gauge similar to the marking gauge.

This one is the Mortise and Tenon gauge. 

Started out with a block measuring 10 1/2 x 3 1/2 x 2 1/2.

planed all 4 sides.

Cut for the fence and beams. This one shows the 3/4 in. cut to size the beams. lost a few pics after this but I then cut 1 1/4 for the width of the fence. After that I cut the height of the fences to 2 1/4. I got 4 beams at 3/4 square.

Found the center and used a bowl lid to get the arc. All three fences are identical.

Close up of the fence. 

Missing a few pics before this but I'll do my best to explain. I transferred the size of each beam to a fence and marked it. Then drilled out most of the waste with a 1/2 in bit. Chopped to my marks using a 1/2 in chisel as the hole was slightly under 3/4 in. Next I drilled a 23/64 hole and threaded that with a 3/8 bolt. Found it to be a little big but holds. Using a bolt works but probably would be easier with a tap. The pin is a 6d finishing nail and is placed a 1/2 in from the end and centered in the beam. I used a 3/8-16 x 1 thumb screw for easy adjustment.

Assembled gauge.

Close up.

This is the beam for the slitting gauge. I marked center and came in 1 1/4 in from the end, then cut on my line. 

I drilled for 2 random machine screws and counter-sunk the heads.

Here I have the nuts set into a hole slightly smaller then the nut. Snug fit but will probably super glue them in at some point.

The cutter was made from a wide piece of .0030 steel banding. Not sure yet if it will hold up but time will tell.

After cutting it out i roughed the shape in on the bench grinder and finished it with a file. Tried to get the same angle and taper on both sides.

With the cutter in place.

Fully assembled.

On the beam I chiseled out a 1/4 in deep dado 7 1/4 long.

Cut a small piece to fit the dado. 1/4 in square.

took a old screw and put it centered on the slide 1/2 from the end. Pre-drilled the hole to avoid splitting.

Another angle.

Using another found screw I placed it on the side of the beam to lock the slide in place. Same finishing nails for the pins. 

Assembled beam.

Assembled Mortise and Tenon gauge.

All three gauges together. I haven't decided on a finish yet. This being my first documented build has taught me a lot, like better documentation of each step! Again sorry for the missing pictures and I hope you enjoyed!