Answer: The most common cause of internal damp is missing pointing to the external brickwork.
Answer: Old properties have no brick cavities meaning the pointing is very important to stop water penetrating into the internal walls. If the bricks pointing is missing you will eventually get water penetration due to the open brick joints.
Answer: No cement pointing should not be used it contributes to internal damp problems and bricks fracturing this is due to the cement mix mortar being too hard compared to the surrounding bricks.
Answer: Lime mortar is softer and more forgiving the cement/sand mix mortar preventing bricks fracturing in cold/wet weather and importantly it allows the moisture to escape from the bricks when they become wet.
Answer: Yes, we have been successfully matching bricks for nearly thirty years.
Answer: Yes, it's often requested but often many areas of an elevation will have been repointed over the decades in various different mortar mixes and it is impossible to get a unison look.
Often it's best to lime repoint an entire elevation for the best results plus it seals the bricks from external rain.