I have only one Parker - 62R. Quite aggressive. The plating is good, but measurements are not. First of all the top plate is not symmetrical. Strangely that doesn't affect blade alignment - always perfect. The second problem is the handle has the hole askew. Seems like a high school project rather than a razor from a company making them since the 70s.
All Parker 3 piece razors have brass handles and zamak heads. Don't know about their TTOs though.
All Parker 3 piece razors have brass handles and zamak heads. Don't know about their TTOs though.