I'm looking for the front "cover" by the dial. It's flat sheet with a dovetail.
Here are the measurements . This part is not badly worn so everything should be close.
2.457" wide on the square end and is consistent down to where the beveled corner starts.
Measures.198" wide on the slot down the center end to end. The slot ends .527 from the end with the beveled corners
On the squared off end the slot ends .502 from the end.
I'll get a depth of the slot in the morning
Its 6.368" long
It measures 5.632 from squared off end to corner of where the beveled off corner starts
The flat in the center of the beveled off end is 1.220" across.
This part is .104" thick
The side without the slot is the bottom.
Both outside edges are beveled to fit in the dovetail of the cross slide.
I cant find my protractor to give a spec on the beveled edges. Refer to your dovetail angle.
The beveled off corners appear to be a 45 deg angle but no way to verify right now.
Monarch didn't appear to try to make parts in common fractional sizes.
I'm not proud of the way I wrote this up. Time and energy ran out. My day starts at 03:00 am
I can draw it up tomorrow if you need a drawing. Let me know.