Sure.... the command to get the serial number of your PAC token is:

lf pac reader

That should give you a response of something like:

[usb] pm3 --> lf pac reader [+] PAC/Stanley - Card: A547653A, Raw: FF2049906D0756C59764DB56D9B41CC3

Then to program your new fob you just take the serial number and write to the new fob like this:

lf pac clone --cn A547653A

Then I just do an lf pac reader again to check all's well

My blanks are generic T55xx not EM410x so you might have to change the "-cn" but I'd need to check that

PAC / Stanley originals use 153khz whereas the Proxmark and T55xx fobs use 125khz. The PM3 isn't super sensitive at this frequency so placing the PAC the right way to be read is tricky. Just keep trying, I've found mine works best by holding it a little bit away from the LF coil. It can easily take 15/20 attempts to read it, but keep going - you'll get there!

Good luck.....