hi guys im looking for a lotus twincam airbox assembly for a cortina if you have any parts or bits please message me

Depends if you have to have genuine or if repro is OK.
The carbie plate, duct and rubber tube are all available as reproductions out of the UK. Check eBay.
The air cleaner box has not been reproduced, as far as I am aware, and is the hard thing to get.
 

I can't help out but when my brother owned a Lotus Escort back in the late 80s, .... And this is what lots of owners done back then is to throw it on the bin and fit air stacks and socks Or paper filters. The reason in my brothers words is the car was not reliable and the rocker cover was usually removed on a regular basis (weekly) to do tune and maintainance , that muffler sirbox got in the way.
All i can suggest is check most sources and also look in usa as they had Lotus Cortina .
Good luck on your hunt. .

Mine is a Kent OHV with twin DCOEs, not a Lotus and I have one of these setups fitted.
Getting to carbies etc is no real issue, it all comes apart quickly and easily.
Love the performance delivered by the DCOEs but the noise became really boring after a while.
I fitted this "Lotus" setup to cut the noise from the DCOEs....made the car much nicer to drive.
On the dyno, there was no noticeable performance difference with the airbox fitted.
 
And, yes, everyone used to turf the setup back in the 70s.
Still remember buying the whole setup back then for $45 !
Sold it with the car back then to.
Took me ages to accumulate the setup I have now whilst avoiding spending silly money.

Airboxes pop up mostly on ebay UK for about $1000.  Surely someone does repros by now.  Or get a V6 Capri muffler and cur the carb hole in the base lol
 

What about..

Lots
Of
Trouble
Usually
Serious