Applied cryptographer, protocol review

We're an early-stage UK company building a mobile application, funded by its founder (just me), which is why the scope below is deliberately narrow.
I'm looking for an applied cryptographer to review a protocol specification before it ships. It is small and specific: three messages, two parties, signature-based, using hardware-backed keys on both iOS and Android. It uses standard primitives only (ECDSA over P-256, SHA-256) and invents no new cryptography; the question is how they are combined. The specification is written and frozen, with test vectors and the generator that produces them.
What I want is a competent second opinion on whether it is sound: six specific questions answered in writing. Not an open-ended audit or a penetration test. The person I'm looking for has either published on protocol security or reviews protocols professionally; being good with crypto libraries isn't quite the same thing.
One piece of contract work, not a role. Under a short mutual NDA.
Email [email protected] by Sunday 4 October with a short summary of the protocol analysis you've done, and I'll send scope, timing and what I'd need from you.