Heathkit (Altec) Legato Speakers - Asking for Viewer Help!

To all my loyal viewers, I could use your help with a woodworking conundrum that I have ran into in trying to restore these old Heathkit Legato Speakers from 1958. Please watch and see if you could provide any guidance.
Legato Specs
16 ohm
Mahogany or blonde finish
-rated to 50 watts
25 to 20,000 cps
41" x 22 3/4" x 34"
195 lbs each
(2) 15" Altec LF Drivers #401-17 which are Heathkit branded 803A's
Altec HF Driver #401-18 which is Heathkit branded 802D
Horn is #400-1 Heathkit Branded Altec 511
Network is Heathkit