67 vw beetle engine bay heat reflection

Hi all new to the forum so apologies if I'm starting something again.

Have a 67 beetle registered and a runner etc but definitely a long term fix up project. Mainly the wife's car and be lucky to get out once a week. Not had it long only since march 20 and done some basics ie oil changes, valve clearance etc put drop spindles and discs brakes on the front for now. As I say this is going to be a long term fix up project bodywork wise and many other things. The carby is a bit worn so for now gonna just potter around with the motor in it and spend as little as possible in that area, but eventually drop it out and replace with most likely a 1500 or 1600 but a fair way down the track.

So question is the rubber engine bay seal is missing so can see through to the floor and obviously this isn't good for cooling. The channels for it are bad so trying to get one in with the motor in I don't think is an option and really don't at this stage want to pull the motor out as I reckon it'll open a big can of worms that if left alone for now shouldn't be a drama.
So does anyone have any suggestions as to what I could do as a temporary measure to improve the sealing and thus the cooling. What I was thinking was poss getting some of that exhaust heat wrap to cut down the heat emitted from the muffler etc but also using some of that aluminum heat shield cutting down and manipulating and screwing in around pretty much where the rubber seal would go. Has anyone done/used similar to achieve a similar result? Obviously I know still wouldn't be perfect but got to be better surely. Any suggestions gratefully received.
Eventually we'll blow the whole thing apart replace any panels required (alot) and do all the sealing properly etc but again going to be a long way down the track gonna start purchasing bits and pieces here and there and once got the majority of things then start ripping into it. Thanks again all.