The Mabie Todd Swan 3173, introduced in 1949, had a short production run and is a very uncommon pen.

The 'Coral' colour is also described, in the Swan catalogue, as 'lined light brown'.  This refers to the faint striations in the colour, particularly on the barrel.  The material has a translucent quality, the top of the cap appears slightly brighter in some lights.  

The pen is a lever filler, it has been fitted with a new ink sac as the original had hardened with age, the pen has clearly not been used for a few decades. 

The pen is in excellent condition throughout.  It has a first class finish and strong imprints on the barrel, section, and feed.  The gold filling on the clip, which is slightly off centred, and the cap band has held up very well. The imprint at the end of the barrel identifies the pen as a '3173', the '3' signifies a lever filler, the '1' is the nib size, and the '73' is the colour code for 'Coral'.

The 14 Ct. gold Swan no.1 nib is outstanding.  It writes with a smooth medium line and has a very responsive flex, giving a good deal of line variation.  Someone with a decent 'hand' would enjoy producing most impressive results with this pen.

Swan pens were made from 1880 to 1960,  they were of very high quality and led the field of English pen makers for much of this time.  All Swans are collectable to some extent but those that have survived in low numbers, or in rare colours, such as this example, are now very highly sought after.