Antwerp BTMC 7019A dial with 7022A mount, where used?

[countryman]

I found this dial assembly. The dial itself was also used on Belgian RTT56 ("kettle") phones: http://www.classicrotaryphones.com/forum/index.php?topic=13634.msg144657#msg144657
The mounting part looks like and add-on type... but for what ?

The dial design is interesting. Taking off the fingerwheel releases the main spring - the dreaded "oooops" moment  - but no fear, it all goes together again easily and the spring tension can be adjusted by a ratcheting mechanism under the finger wheel! That's why it has the "spokes" in the center. A really nice concept that I did not know before.
Altogether the dial looks fairly modern,so I assume the mounting assembly was not designed as a retrofit for wooden phones or the like. Maybe for central office equipment?

[FABphones]

Possibly used to attach a dial to a formerly CB phone. I have seen similar variations on phones and switchboards.

...the spring tension can be adjusted by a ratcheting mechanism under the finger wheel! That's why it has the "spokes" in the center. A really nice concept...

Could you please step us through the process.

[countryman]

I have put the dial on a RTT 56B phone now, I originally wanted it for that purpose. I will preserve the mounting part for possible later use or trade-in...
The first pic is the phone with the backing plate for the dial card taken off.
In the second pic, the fingerwheel is taken off, showing its underside. The screwdriver points at a little cam, limiting the travel of rotation. Its counterpart can be seen next to the 4, inside the number ring. There you also see the ratchet mechanism: A round plate with spring-loaded "wings" on the outside and 4 notches on the inner side driving the main spring.
In the third pic the wheel is back on. Now the winged plate can be turned clockwise with a pointed object. The wings will engage with any of the 5 spokes and hold the assembly in that position, thus tensioning the main spring. The uneven spacing (2 wings, 5 spokes) will allow a relatively fine adjustment of the spring load with minimal effort.
Before dismantling the wheel it is recommended to push down the ratcheting wings a little to fully release the main spring. That will avoid the "ooops"!

The last pic is Matilo's dialcard from the thread I linked to in the initial post. I took the liberty of cleaning it up a little, to print it out for this phone.
BTW the handset seems wrong for an RTT 56, possibly off of an older BTMC phone. There should be an F1-like handset. The usual mix of parts on these decorator phones.

[RDPipes]

Great information here, specially since I have just acquired a phone with this dial in need of rewinding.
Coincidence? I think not.

[countryman]

I now managed to wire the dial to the phone:
Link to the diagram section

[TelePlay]

The wings will engage with any of the 5 spokes and hold the assembly in that position, thus tensioning the main spring. The uneven spacing (2 wings, 5 spokes) will allow a relatively fine adjustment of the spring load with minimal effort.

When releasing main spring tension, it's important to count the turns of tension put into the spring. Of all the dials I have disassembled, they all had 1 1/4 to 1 1/2 turns put into the main spring. Dialing 0 adds another turn.

Under-pretension won't allow the dial to return to stop within dial PPS specs and over-pretension will put excessive wear on the dial governor.

Each manufacturer had its own patented way of mounting and tensioning the main spring in their dials but all seem to have used 1 1/4 to 1 1/2 turns of pretension.