It has occurred to me that moderating the posts of new users would not be too onerous a restriction to impose for this forum... with one important exception.
But making that exception would help solve another problem this forum has, in addition to the spam problem.
So here's my modest proposal:
New users would see their posts await approval before appearing on the forum - usually, only the first post would need to be so delayed - except if they're posting to one of the Type ID boards.
Because if you want a Type ID, you may be in a hurry. And this would be of a huge benefit in keeping the Type ID requests in the right place!
So, as I said - two birds with one stone.