So, I am happy to say that I have three healthy Chestnut young. Two are dark Chestnut and the youngest one shown on the right is a few shades lighter.
I bought some egg and biscuit and still the adult Bengos are not very interested in it. They readily eat and feed with the sprouted seed that I give them and since it is spring I have been feeding them green seeding grasses that I collect from around the local area.
The pair of light/dilute chestnuts in the other cabinet still do not show much sign of settling down to nest but for the time being I will continue to also feed the sprouted seed and seeding grasses to encourage the spring breeding instinct. I am still reserving the opinion that the finch that I think is the Hen is too old for breeding or is in fact a Cockbird.