Reddit reviews Ke Number Pad, Mini Wireless 22 Keys Multi-Function Numeric Keypad Extensions for Laptop/Desktop/PCs/Notebook

So the 10 digit bit should be fine, I would create and enclosure for the pi in the end of the box, you will need a number pad, carve an insert out of the wooden box

Numberpad:
https://www.amazon.co.uk/dp/B01H4PW8PS/ref=cm_sw_r_cp_apa_i_RAWzCbJ5DPQ1C

LED Display:
https://www.amazon.co.uk/dp/B06XJ9ZX17/ref=cm_sw_r_cp_apa_i_hCWzCb6D4W1JP

Smart Lock:

https://youtu.be/TX_WQMYc0SU

Python Script:

This will interface with GPIO and will contain a string with the access key, you read the input from the keyboard, output the entry on the LED display and finally check if user entry matches variable

Here's the STL. The keyboard was a cheapo I bought locally which I can't find online, but another user in these comments found a really similar looking one off amazon, here's a link for that. It's similar enough that I bet you can get away with tweaking the scale in the slicer at most.

My first thought was to get a USB number pad like this and just stick it to the left hand side of your keyboard.

Keyboard used: https://www.amazon.co.uk/Jelly-Comb-Wireless-Receiver-Compatible/dp/B01H4PW8PS/ref=sr_1_3?keywords=wireless+numpad&qid=1563543332&s=gateway&sr=8-3

SLT file (maybe?):https://www.thingiverse.com/thing:3327037