Unusual London bust type - holding globe

[Heliodromus]

I just received this one, fresh out of the (e) Bay.

 

RIC VI London 162 R (bust type U - laureate, helmeted, cuirassed, holding globe)

The type dates to 311-312 AD in the run up to Constantine's Italian campaign vs Maxentius. Per an Adventus type in the same issue it seems that Constantine may have been in Britain collecting troops at this time. There is a huge variety of bust types (RIC lists 30 !) in this issue, many martial as befits this preparation for war.

The interest of this new coin is the bust type, which while known is extremely scarce due to the globe - possibly just this one die. RIC lists this bust type only on this type, RIC 162, based on a single specimen in the Oxford Fitzwilliam museum. Subsequently a second coin with the same bust but different PRINCIPI reverse type, from the Boursies hoard, was identified by Helen Huvelin in her "Les deux emissions londoniennes" study of this and the following issue, with Lord Stewartby later noting this Boursies' coin being an obverse die link to the Oxford one.

My coin in turn appears to be a die link to the Boursies' PRINCIPI (Laufaurie 311 = Huvelin 128), below, so these three coins (Oxford RIC 162, mine and Boursies PRINCIPI) are all from the same obverse die. I'd be curious if anyone has seen any others with this bust type !