I bought this used for my Mesa MKI reissue combo- to make it into a head. It's made from African Mahogany and is in great shape.
chassis measurements for the MKI are
17" wide across the front
7 7/16" front to back
2 1/4" Deep
chassis holes center to center are 5 3/8"
see pics on reverb
https://reverb.com/item/36798008-custom-head-shell-african-mahogany-hardwood-for-mesa-boogie-mki-amp-chassis
chassis measurements for the MKI are
17" wide across the front
7 7/16" front to back
2 1/4" Deep
chassis holes center to center are 5 3/8"
see pics on reverb
https://reverb.com/item/36798008-custom-head-shell-african-mahogany-hardwood-for-mesa-boogie-mki-amp-chassis