Further to previous post, I thought that perhaps a good near-infrared image of this galaxy might make the overall structure clearer.
I just Found this one on the internet, taken with Gemini South telescope and the FLAMINGOS-2 instrument in December 2011 in good seeing.
It is a composite of J and H and K exposures (1.2 microns ; 1.6 microns ; 2.2 microns)
The central small mini-disk is extremely obvious in the low-extinction near infrared regime.
But why don't the two principal spiral arms link to anything as they curve inwards??!? One possibility is that they might plausibly link to a weak ring structure surrounding the central small disk.
(It is quite common for spiral arms in galaxies to start from a ring structure, rather than from the very centre of a galaxy)
Another very odd thing about this image is that if you turn up the brightness and contrast, there is a very strongly rectangular structure in the central parts of this galaxy.
Its all quite puzzling really, as nothing is quite "as it should be" in this galaxy.