I think you should publish whatever code you have so far. People are not expecting finished or polished code, just some evidence that something is actually being done. Weekly updates to this unfinished code will show progress is being made. This gives people confidence, most scammers won't take the time to write real code. I know that some will criticise it but most will appreciate and be willing to donate. You will break a trend here of devs not publishing code and that will win a huge amount of support. I know I'm going on a bit but it is so hugely important.