Yes LPC as you put it would normally be called a Line Check which is different to the LPC as Licence Proficiency Check which involves Licencing action for the revalidation of the type and IR.
The OPC is a company (part Ops) requirement valid for 6 months and must be done by a CRE/TRE. Every 12 months you will do a combined LPC/OPC with an examiner to revalidate the type and IR on your licence. The type and IR as I said are valid for 12 months and will be indicated so and signed by the examiner in your licence.
Does that help?