My circumstances were very similar to yours, resident in a small approx 50 dwelling private development of up to 50 years vintage, POTS all UG distribution, un-ducted direct burial armoured cable (DIG) to each dwelling.
OR sub-contractors spent approx a month at the beginning of last year running fibre throughout the estate using existing ducting where possible and installing quite a considerable amount of new ducting where necessary for the fibre runs, individual property "toby boxes" where only installed at the opposite side of the street to the main existing cable duct (footway chamber) runs.
In my case a 4 way fibre CBT was installed in the footway chamber directly outside my front garden wall, there were no property exits from this chamber the POTS being fed from the footway chamber at the adjacent property.
So what happened with my FTTP install last month was, OR sub-contractors appeared approx a week before the fibre install date and installed a toby box directly beside the footway chamber with direct ducted access to the chamber.
On the install day, a pair of OR sub-contractors arrived, drilled throught the toby box under the garden wall, ran ducted fibre across the front garden to the chosen house entry point, I had already installed a duct under the path and drilled through the wall, installing the ONT.
From your description, I would imagine that you will also require the installation of a toby box as some method of exit for the fibre from the footway chamber where the CBT resides is obviously necessary.
I have observed quite a few recent FTTP installations in our general area, with UG distribution even where POTS ducting exists a complete fibre run to the existing phone master socket is rarely achievable, in most cases the existing POTS duct is broken into as close as possible to the property, the fibre extracted and run externally to the new designated entry point.
Of course your particular area may well have different installation methods but the principal is certainly the same.
I have no idea if my area (NW Northern Ireland) was part of any form of grant scheme for this particular fibre installation.