The first public service train on the new track ran on 8 January
A bid to raise £8.6m for the work to complete the Welsh Highland Railways has been launched.
Following the completion of the line between Caernarfon and Porthmadog last October, further funds are needed to improve the rolling stock and stations.
Andrew Thomas, spokesman for the Ffestiniog and Welsh Highland Railways (FWHR), said they also want to build sheds for the locomotives and carriages.
"Most importantly, we need to widen the station end of the Cob in Porthmadog to give room to build a second platform for Welsh Highland trains," he said.
"At the moment, we can't have both a Ffestiniog and a Highland Railway train at the station at the same time.
"So anyone arriving expecting to catch an onwards train has, of course, just missed it.
"We're hoping this will be sorted out by this time next year."
The appeal will also pay for the new station at Beddgelert, as well as upgrading facilities in Blaenau Ffestiniog.
"The key thing is to make the passenger experience better," said Mr Thomas.
"We're about selling the view out of the window of the train, and people expect a level of comfort which we want to provide at the stations, too."
The drive to encourage monthly donors will be spear-headed by the Ffestiniog Railway Trust Appeal.
The Caernarfon to Porthmadog track was finished in October 2010
Andy Savage, who set up the appeal website, has been involved with the steam railways of north Wales since his childhood.
In the big appeals he's helped run so far, Mr Savage always been impressed that the largest number of donors come from the LL postcode area, which covers most of north Wales.
"We're delighted to get that support from north Wales," he said.
"At the time we were rebuilding the railway there was, inevitably, opposition to it; it's always easier to see the objectors rather than the supporters.
"And in the end, the railway contributes a lot. A piece of work by Bangor University said it puts £10m into the local economy."