Usually, closely — and where an exact match isn't available, we'll be straight with you about it. Older bricks in particular are often no longer made, and colour varies even within a batch. Reclaimed bricks are frequently the best answer for period properties. Mortar matters as much as the brick: getting the colour and joint profile right does more for a seamless match than the brick alone.
Repointing is right when the mortar is receding, crumbling or letting water in — not simply because it looks tired. The big risk is using the wrong mortar. Hard cement mortar on a soft old brick forces moisture to escape through the brick face instead of the joint, and the bricks spall and crumble. Older Sussex properties often need lime mortar. Repointing done wrong causes more damage than leaving it alone.
Within limits. Mortar doesn't cure in frost, so we don't lay bricks in freezing conditions or when frost is forecast overnight — the mortar will fail and the work will have to come down. In cold-but-clear weather we can protect new work with hessian and sheeting. Sustained rain is the other constraint. We'd rather lose a day than build something that fails in its first month.