Rotatoned NE No.1 with BPO dial - help!?

[Tribune]

Goodness, its been WAY too long since I've been on the forum.

Been dabbling in my other hobby - 4x4 off-roading. Building a big expedition truck.

Anyway, I need some direction and assistance. My aim is to have a nice Northern Electric No.1 in my office. But my office system uses an IP PBX. So . . .

I have an ALGO 4900 USB analogue terminal adapter attached to my VOIP deskphone (Avaya 1120E) and my NE No.1 connect to that. Works fine, but the ATA doesn't accept a pulse signal.

So, I need to fix a pulse-tone converter in there. Easy job on a 302 or No.1 with a 5H dial, but this is a BPO dial that I want to keep. Right now, figuring out the wiring is beyond me.

Can any one help!?

Really would like to have the old NE No.1 at work to complete my vintage office look. And yes, I know some folks think that adding such things is close to heresy, but under such specific circumstances, it is what I need.

I'll upload a schematic for the No.1 with BPO dial as well. An annotated version for the Rotatone addition would be exactly what I'm looking for.

Many thanks
Mark

[Tribune]

Here's the schematic

[Owain]

The leads are:
1. Orange/Red. Positive supply and signal line. T2 on 4-way term block (green/tip/0V)
2. Blue. Negative supply and signal line. - L1 on induction coil (red/ring/-50V)
3. Pink (White on some units) Common connection to dial. - D4
4. Orange. Connection to pulse contact on dial. - D5
5. Brown. Connection to shunt contact on dial. - D3

This is based on
http://www.oldphoneworks.com/files/oldphoneguy/rotatone/Rotatone-GPO746.pdf

which is a 746 tele. If you're using a different dial or the dial contacts aren't numbered, you'd have to transpose your dial contacts to the one shown on that diagram as we represent dial contacts differently.