You’re right there Big_Dave, regulations change often with most countries in SE Asia. Seems to be no problem if coming from Thailand with Thai registered bikes, same for VN and Laos. If they turn you back at one border, try another!
We just had some friends over from Koh Chang and Hua Hin - they crossed over and back at Had Lek with no issue. OSmach also good, just avoid Poipet! Have your paperwork in order, be respectful and sling some tea money and you’ll get across.
Will try to find more info on this, but regardless, it will be an awesome Bike Meet.
Cheers
Wont be much of a Bike Week if the Cambodian customs dont let riders in from neighbouring countries.