Bit of progress over the weekend,

the backbox attachment part of the main cabinet was fairly secondhand,delaminated ply and support underneath all cracked and broken, See first pic

So I decided a decent repair was in order,

Removed from cabinet and seperated the upper and lower pieces of the assembly,

and knocked up a replacement lower piece out of solid timber,

and also repaired and reinforced the cabinet in this area.

should be staunch now....