jSeblod CCK is compatible with any Joomla content plugins. You can easily use any jSeblod CCK field as a parameter of your plugin.
Stop to ask your client to remember a special code like this {mosmap width='500'|height='400'|lat='52.052312'|lon='4.447141''}, you can display a nice form included in your content type to select easily all parameters of the plugin.
Create a Joomla content plugin field and insert in the default value the syntax of the content plugin:
{plugin parameter1='#my_cck_field1#' parameter2='#my_cck_field2#'}
my_cck_field1 and my_cck_field2 are names of CCK fields used in your content type.
Insert this content plugin field only in the Content Panel of your Content Type.
Be careful to respect the original syntax of the content plugin and just insert the name of the CCK field between # symbol where you want to put the value of a CCK field.
Verify that jSeblod CCK content and system plugin are first items in your plugin list.