I loved my CB7 but why go backwards. I bought mine in the 60's.

Your MX must be 15-20 years newer.

Other than the front controls and motorized focus, the MX is an evolution of the CB7.

Note: lamphead parts for the CB7 are larger than the other 4x5 Beseler enlargers. The condensers are bigger in an effort to get improved 4x5 corner illumination. MC/H/MX/MXII/MXV color and diff. heads require an adapter. Wiring some modern timers thru the front controls may be tricky. it is a 50 year old design.

The only real upgrade from a MX would be a V model. Beyond that its a Durst 1200.