Hi Troels,
Having build previously the bookshelf 3wc  for my study and the faitel 3wc 10 for my son i was looking for a new project.
In my living there i have a rebuild from the kef 104AB  ( floor standing design) wich had a good WAF factor and somehow the passive bas was doing well in the room.
Being fond of transmission lines i build a kef als 50 from scratch and when finished i realised that the 50 years old speakers couldn’t keep up with modern speakers in terms of quality in sound and power handling and SPL.
First i had the idea of mounting the bookshelf speakers in the line but even i thought the cabinets were to big.
So i sold them. I had to quit being stubborn and just build the discovery 861.
Good size, 3 way, and as far i could see from the builders reviews doing well !
I changed the design a bit, bit smaller and deeper, keeping bass volume the same, mid was increased to 19 liters ( 16 original).
Had some difficulty designing the dustcovers , think they suit them well.
Made the feet of simple cheap factory feet, with 40 mm plastic drainage pipes covered in black leather.
Some little tips for cabinet builders, In Holland we have the action, cheap shop where they sell these scissors for 5 euro’s , very suitable for cutting  the felt.
Made a access for the speaker terminal at the bottom of the cabinet.
I made the cabinet of 18 mm mdf and glued 2 mm thick oak veneer on the mdf.
Using thick veneer ( 2,3 or 4 mm ) is very do-able for DIY and easy for correcting minor flaws.
After a little burn in I am very satisfied with the sound, clear, good stereo-image, enough bass, handling well in the living, good value for money, HAPPY.
Thx Troels, keep up the good work !