It is a homebuilt so it must be Annex 2. Each European state has its own rules for Annex 2 aircraft maintenance, so, there is a lot of conjecture as to whether it is legal to permanently keep a home built aircraft in a state within which it is not registered.
There is a carefully considered article from the LAA on this subject which is particularly relevant to how the UK regulations treat the issue, an extract follows:
TRAVELLING ABROAD IN A PERMIT AIRCRAFT
There is a special case for certain aircraft on the LAA fleet to which the CAA has issued an EASA Permit to Fly (albeit administered by the LAA). This affects only a small number of types: Fourniers (all marks), Bolkow 208, ARV Super Two (factory-built examples only) and Slingsby T61A. These particular aircraft are classed Annex I by EASA, and should by rights hold a full EASA Certificate of Airworthiness. However, due to their history of operation on a PFA/LAA Permit to Fly these particular, individual aircraft were ‘grandfathered’ onto EASA Permits to Fly, administered by the LAA. These Permits are recognised by all member states, and these aircraft therefore have a right of flight in member state countries. Oct 2016 Page 1 of 23 We advise not to allow an LAA Permit to Fly expire whilst the aircraft is abroad. In the event that this does happen, contact LAA for advice on special procedures that will apply for renewal.
The german registered aircraft may be treated very differently
Last edited by Fl1ingfrog; 2nd Dec 2018 at 19:28.