Succeeding spot after penalty on try?

[tskill]

Under NF rules, where is the succeeding spot when there is a penalty by B on a successful try and A takes the result of the try and elects to have the penalty enforced from the succeeding spot?

My thinking is the succeeding spot would be the 40yd line of A since this is where the free kick would be from, so does this then mean that A would be kicking from the 50yd line if the penalty was lets say a 10yd hold? And then would the R restraining line be R's 40 since it would be 10yd's apart?

Is this correct or all wrong, and are there any other penalty enforcement quirks that need to be taken into account for a penalty on a successful score that results in the score counting and the penalty being enforced?

Thanks