SOME HELP CONSTANTINE I AE3.

[Corduba]

Good morning, here in Spain.

I need some help with this Constantine I.

Weight: 3,43 gr.
Size: 20 mm.

Observe:
CONSTANTINVS P. AVG

Reverse:
SOLI INVIC-TO COMITI
In the field: T - P
Mintmark: PLN.

The problem I have is the "P" on the right side of the field. I can´t find this control mark. The normal one is a "F", but this is clearly a "P".
The closed i get is RIC VI, Londinium, 126.

Best regards, Ignacio

[Corduba]

Maybe I found it. 

The mint mark could be MLN, not PLN

An the field is S - P.

In this case the coin is RIC VII, Londinium 56.

Bets regard, Ignacio.

[Heliodromus]

It looks to me more like PLN than MLN.

PLN S-P would be RIC 111.