Quoted from Rdoyle1978:that's a pretty great idea! Are you working to sell these, or would you be ok with sharing the .STL?
I'd suggest a very small gentle slope on either side of the door which could be painted green. It will give it more of an impression of it being in a hill, and look less like a clock as you pointed out. Not exactly accurate to the film or book, but given the space to work with, i think it's a good compromise.
There's a lot of detail in the back of the playfield there that can get lost; this will definitely look perfect there, as a literal 'doorway'.
I've gotta see if the final version can be a potential viable product. If it takes two+ hours to post process and paint, it will probably cost too much (I just don't have that kind of time to dedicate). Hopefully I'll figure out a good process to make them at a reasonable end user price. The surrounding models look so good on Hobbit, I have to make sure whatever I make looks as if it came from the factory. Stern Pro pins are easier to make mods for since there are hardly any other models on the playfield to integrate with
I will for sure though get an .STL version out there for all to print free on Thingiverse! I did this for my last mod for GoT Pro (link below) and it worked out good. You can print a sweet version for free, or buy the more complex lighted version. I am going to try to stick with this same concept for Hobbit: