Is this with all materials or just certain types/ thickness?

the only time I've had problems is miss matching oem with aftermarket.

I looked into this years ago, a long arm machine with a cnc bed will cover about 600mm wide by about 900mm long (or more), a long arm machine is basically the smallest you can go to cover seat centres and doors for auto work which come in at around say £35-40k anything bigger in bed size will jump in price.

all the usual names offer a product, juki, pfaff etc and there's richpiece and ksl

from memory the a original hood has a piping around the window and the hood material tucks under the piping then heat sealed, you need to get a pick tool and unhook the top material out of the piping then it can be unzipped refitted etc

This picture must of been taken after it left the trim shop?

There’s absolutely no need use backing tape on a dash, if the leather shrinks due to heat no “backing tape” will help!
When you stitch a seat base together which takes the biggest loads do you back it?

To me it looks like the dash wasn’t cleaned up enough before the close cell was applied or when fitting the cover was lifted a few times with glue applied. But to answer your question I wouldn’t let that go BUT was it cheap or top $?

The key is to make the rear section fit as it should, centre the window and pull it hard around the bar to get the lip over the body. Then deal with the front, just be carful not to over tighten it front and back or it will be a bitch to shut, also if it’s been messed about with in the past they have a habit of breaking the frames! make sure it all works as it should before you fit or your be in a world of pain! Good lick

check the B pillar arms for cracking before you get to into it

i have a cone from aston so i'll have a look for you

Why not trim it yourself?

Gah kits have always had the right details in them.

All hoods of this era would have the excess material what i call "paired out" by that i mean you open up the tips of the shears 2-5mm on the end, hold onto the excess material and slide the shears around the seam, with practice your get a perfect 2-3mm cut parallel to the seam....obviously a sensible pair of shears will be required so the hole thing can be done in one motion and your not hacking at it!

did you make a pocket for the window or are you cutting off window and top material?

As said above the car has had some work

Why not build a box racking to spec of the space you have or the amount of material size you may need? Sorted in colours, manufactures etc etc

That’s a open ended question and everyone with have a preference for various reasons, I do a lot of edge skive leather dashes and non scrimmed foamed covers. My 2810-7 juki will run the smallest to the biggest thread ever needed and deal with covers scrimmed in 3/4 +inch foam no problem for a top stitch, yes I can dial the machine to run lovely on a edge skived leather or single alcantara BUT a needle feed machine is just better at the thinner stuff

Needle width on a twin will deepend on what sort of automotive seat you see daily or whatever you like to use.
From the feet pictures your using a needle feed machine? to run a different needle width the machine needs to be set up for it. sorry I'm not sure if you're aware?

with that sort of material your looking at 'production' quantities?

the only thing i can suggest is try a different size piping/welt foot, i use a foot from 4-8mm depending on the job/piping thickness.

To me it sound like the piping/welt foot is to small or the machine is not walking high enough?

what air bags do you have? if it's a red steering wheel bag/cover for lamborghini huracan then sell it, if its a side seat airbag for a toyota prius youtube it lol

I’d say there’s a element of automation for the mass produced stuff, the final Lacing I would say is by hand.

The reason I say this is one car I own (mk1 focus RS) the wheel seems to have gone through some sort of heat process as the colour/finish melts. Also the glue underneath indicates to me it’s been through some sort of process.

that's with a twin stitch but same principle... you won't get a deep square edged flute, butted together with out making a pocket.

merc flutes (oem style) can be done 2 ways...

sew the pleat lines straight onto leather/vinyl with calico on the back, mark a line up the centre of each pleat on the calico, move the face material out the way and run a fold on the calico down the centre and machine 4,5,6,7,8 etc mm out of the calico...this will give the pocket then stuff with a square edged firm stuffing.

or mark the calico and sew directly to the sew lines, rather than folding and sewing the calico.

the ends of the leather need to be pleated to get the leather to the size of the base material as you have say 40cm width in the calico but the leather on top made into a pocket is 50cm, is is done in a Z pattern.

The piping has been sewn to the flutes and the horse shoe panel has been relive cut and pulled round the curve while machining, which gives it the natural shape of the foam

is your machine new? if so you will need to grind the knife down slowly so it has the curve of the grinding stone not a 30 degree (ish) angle they come with, running a marker pen on the bade with let you know when its the right shape

id mark before the radius/after and the centre