Would there be much involved to bring it back to 1800's, I assume building itself would remain much the same, just the road and vehicles?
Well that is a good question, especially as it is on my medium-to-long term to-do list.
The main work involved in 'going back in time' would be the replacement of the road layout with perhaps dirt tracks and horse pulled carts replacing the motor cars. I think there would also be a requirement to build 2 tall-ships with plenty of cargo being loaded/unloaded.
As regards the building, perhaps the blue doors would need a colour change and certainly some probably should be left open. If so that would entail from reworking on any internally visible areas as the building is a shell on the interior.
On the roof there would be a need to add a bunch of large chimneys as can be seen in this old image, it seems taken during its construction.