Isn't this the same thing, just an electronic copy rather than a paper copy of your maintenance, servicing and assessment record? Am I missing something?

The document isn't the point; the point is whether someone has actually looked at the equipment and established whether or not it has suitable guards, emergency stops and so on and what training the operators of it need. A maintenance register doesn't relate to that.

Risk assessments are supposed to be reviewed periodically to check that all the control measures are working and that nothing has changed to invalidate the risk assessment. So I don't think a one-off declaration that the equipment has previously been considered OK would cut it. You say that "The document is filed and never sees the light of day again unless requested during an audit or inspection." I think that's the problem here. That's not how it's supposed to be! If nothing much is changing with or around the process, and it's OK to start with (which I think you believe to be the situation here?) the reviews won't need to be very frequent. But if the reviews aren't frequent, no one will remember the previous assessment and so it will need to be written down in some detail for the reviewer to be able to check it is still right.

The engineering manager at my establishment makes two very poignant statements about PUWER assessments and insists on both of them being addressed P = Provision: That is, is the machine designed to do what it is required to do and has the correct safety equipment installed to make it safe to work i.e. guards, interlocks, etc and do they work U = Use: Are the operators involved in the assessment with regard to its operation and how they will use it within the confines of where it is situated. In addition, dop they know how to use teh safety features correctly and know where items such as e-stops are located. Therefore, the use of just maintenance regards in my opinion would not fully satisfy the PUWER regulations.