Ok, I've been pretty busy recently (new school year coming up!), and haven't got a lot more to say. To answer the OP's question: Yes, some ELT sources would call the sentence a mixed conditional as it contains a combination of verb forms that do not appear in what are called the 0-3 conditionals. As to whether it is grammatical, yes it is; and I am a little surprised that you suggest in your last paragraph that the OP not emulate it. Following Lewis, we can justify the verb form in each clause based on the communicative intent of the speaker. The statement could be interpreted as follows: …