There is one gig for mastering: this one. Check extras for more.
If I'm not a good fit for the project, we can either discuss your needs, or I can point you in the direction of a (hopefully) more suitable engineer for your needs.
The 'warmth' added by vintage, analogue equipment is due to the gear not working properly anymore, in many cases. What you're hearing is reduced high end, which automatically emphasises the low-mid frequencies. Analogue gear is not necessary to achieve great results.