I think if you wire the A1000 KB correctly to a PS2/USB adapter that was design for an A2000 KB to work on a PC, it will work.
That being said here is a Arduino project that does that also.
http://forum.arduino.cc/index.php?topic=139358.0Also here
http://www.l8r.net/technical/t-keyboard.shtml"Amiga Keyboard Pinouts
Pin CDTV A1000 A2/3000 CD32 A4000
1 GND +5V KCLK DATA I/O
2 KBDATA CLOCK KDAT TxD n/c
3 KBCLOCK DATA NC GND Ground
4 Vcc GND GND +5V +5VDC (100mA)
5 KBSE +5V CLOCK Clock
6 RxD n/c
GND is ground.
+5V is positive 5 volts.
KCLK, CLOCK and KBCLOCK is keyboard clock.
I/O, KBDATA, KDAT and DATA is keyboard data.
TxD is RS-232 Transmit data.
RxD is RS-232 receive data.
KBSE is keyboard sense.
A1000 is RJ12 jack.
A2000/3000 is a 5-pin DIN female.
CD32 is a 6-pin miniDIN female.
A4000 is a 6-pin miniDIN female.
It has been reported that some very very very early Amiga 2000 keyboards
have a different pinout. If you can show me some documentation on this
I would be happy to postit here."