A few issues encountered here. So will try explain what I have done / found
Firstly fitting the deck plate into the hull.. it didnt fit. There are two parts that protrude up from the hull suspension steps that are supposed to mate with two slots in the deck, but the deck slots are waay to small.. need to trim the slots (circled in red)

A better fit with the slots enlargened. what worried me is if the floor should be flat here and not have these lumps?... (but why would there be slots if thats the case?) Also you can see why I pre painted here..

speaking of pre painting.. I test fitted the photo etch sides, and saw a massive raw plastic gap..the instructions give no clue to what colour this should be so I assume white... back to the airbrush...

the un named part that needs to be painted traced in red..

to be on the safe side I decided to paint the whole tub white except for the nominated black parts... (masked off)

the tub repainted white.. (and some other parts)

also started cleaning up some overspray.. and installing the cabinets.

So the first kit instructions actual typo error I have discovered - They have mislabbeled part PE-23 as part PE-13, which is a seat belt, no big deal as I doubt anyone will try install a seatbelt where a rectangular metal plate should go!.
However be careful in the same step- as the two plates (23 and 24) are different widths.
there are two photo etch plates that go under the driver and co drivers feet. one is wider than the other so they can only fit on one side each - they are not interchangeable. So it is important to get this right or if you put the small one on first in the spot the instructions say , you will have to lift it up later to fix it.
Here is a picture of the plates in place, and the actual part numbers off the photo etch sprue.

here is the photo etch sprue (sorry its painted black, and the parts are missing but the silhouette is there)

Part PE-23 is wider and will only fit on the port side, and part PE-24 is narrow and will fit both sides, but should be on the drivers side (starport). Just be careful to fit them in the right place or as I said will have to dig one up.
the photo etch plates at the rear also have a fit issue for me. I found they are about 2 mm too long, and had to trim both of them with a pair of scissors.. the red circle shows how much it over laps, but I trimmed other end as it sits flush.

scissors cutting - was nice and easy to cut so its soft PE...

a nice fit of the sheets..

So I did a test fit of cab onto hull.. and up popped another issue. I hope this one is supposed to be like this, but I doubt it.. The Air conditioning duct seems to protrube into the cupola hole. I doubt very much that its designed like that in real.. but could be wrong, maybe the cupola fittngs will reduce the hole size , but its something I am concerned about . Oh and yes I do have the bracket the correct way around (that holds the duct) .

The underside of the cab and the mating Air conditioner duct

Now getting the dashboard to line up. Tough to do this as the dash does not have any positive mounting points.. It can be mounted forwards or backwards on the chassis tub about 5 mm so getting it right calls for lot's of test fitting.

heres a pic of dash slid rearward. Can see asmall lip protrubing from under it.

And where I reckon it should be, that is flush with the front edge of the floor it sits on. (I have some tamiya tape there), no protrubing lip as in the pic above.

Now next issue - and this has caused me to pull up for the night. The dash controls. There is option for two dashboards in PE on the instructions. the difference is one has all the dials in place the other has holes where the dials should be. But I had to go look for what colour the dials and gauges are. I prefer to use the hollow guages but there is no dials/guages on the decal sheet. Unusual. SO have to paint them in, and of course the dash mounting point is pre painted green so need to repaint the underside of mounting point white or black or whetever the guage back grounds should be.
Here is a picture I found of the actual dash colours and layout.

With that work in mind, I will do the seats and dash tomorrow. And tidy up a few other details, If there are simple things like cables, plumbing, and small features to be fixed, then will do that aswell. Once the interior is constructed.. will also have to weather it as it will get sealed up very soon! Then the seats have peculiar decals, followed by all the seat belts..
PS part A1 is missing the vent wings left and right leaving a massive hole in the air conditioner that sits in the center console. Sams blog has a great pic of it.
Adam