With the original negs a big Mac should be able to pull out most of the tint for very little loss of clarity. That is because there is still more information in the image than can be digitalized. We were doing this back in the late '80's, though the machine was humongous in those days. That firm was bought by Saachi after they produced a scanned and printed image of a Degas painting off the proofing press. Did a limited edition of a 100 copies if I recall. I preferred the Christmas card of their receptionist in a pram being pushed by the Queen. Very early perfect picture splicing to swap heads and scale. Pretty ordinary computers can do this now but the really good programs can re-write history. So you really cannot believe what you see in the papers anymore.
Its back to time. It takes the operator time to manipulate each scan to maximize it. That is chargeable. Such is the overhead on labour these days time cost an awful lot of money. So far I have probably saved £10,000 in bought time and tax by doing up the house myself. The downside is its taken me three months to do half the house. But effectively this year I will have 'earned' £20,000, tax free, by doing the place myself. I would have needed to earn some £27k after direct and indirect tax to have achieved that too. Thats about a Schmitt and a half! Sadly you cannot afford to put jobs out if you can do them yourself anymore. It just is not cost effective.