Tannoy gold 12" cabinets

They are beautiful. I am not knowledgeable enough to suggest improvements on those. 

I would sign up for the email list on the the Tannoy blog that hans Runs.

https://www.hilberink.nl/codehans/tannoy100.htm

You will get exactly the information you need as i am sure it has been done many times before. Maybe just some internal bracing and yes get the center of the speakers to ear level for your listening position. Probably around a 22" quality speaker stand. 

It will be about a month to finish them as my cabinet shop is backed up at the moment. 

I have 12 inch hpds in new very heavy birch cheviot cabinets. They are not very large.  The sound is amazing. I may get a second set of speakers for another system in the future but I’ll never part with these. The vintage tannoy sound is special. Fwiw think Nelson pass uses vintage tannoy in his own system. 

i think Nelson is hooked on the JBL Jubal, but who knows..
stick w the Tannoy and your cabinet project..

Islandman, Whidbey is lovely..stop by for a listen IF ya get down my way to Seattle sometime.....I have room for just about every loudspeaker faith..

and Van Isle is magical....spend my summers chasing fish around at rock....hence my moniker..

have fun

and dont forget really do try to get tweeter at ear height, no matter what the KEF dealer says...ha