His sons Henry, 9, and James, 13, got to clamber on and sit inside the W-class tram that he painted in 1986 as part of Melbourne's Transporting Art series.

Creative Industries Minister Martin Foley and VicTrack staff showed the boys and their mother, Fiona Larwill???, around the yards this week.

Mr Foley, by coincidence, went to the same high school as Mr Larwill; his brother was in the same year as the artist.

He revealed during the tour that the government is in negotiations to run a replica of Mr Larwill's mural later this year on the Yarra Trams network as part of Melbourne Festival's revival of the art trams.

It hopes also to use replicas of original works from the Transporting Art series, which ran from 1978 to 1993, on contemporary trams in future years.

The visit came more than a year after the family asked to view the tram, which Mr Larwill - an expressionist painter and co-founder of Melbourne's radical Roar Studio - had given up for lost before his death in 2011.

Their request was initially refused by VicTrack for safety reasons but was later reconsidered.

The family only learnt of its last stop after reading a story in The Sunday Age in late 2016 that mentioned the Larwill tram was held in storage at Newport.

Up to now, all the boys had seen of the tram was a ceramic replica, including a miniature of the anti-war mural painted on its exterior in their father's distinctive larrikin style.

The mural, painted in oils, has stood up surprisingly well; its colours are still quite vibrant and the artwork remains largely intact, bar a few small graffiti tags, including a tiny squiggle of a signature written in pencil.

The tram, which ran on route 1 between East Coburg and South Melbourne, has sat in the rail sheds at Newport for several decades (guarded, according to VicTrack staff, by an elusive fox).

Mr Foley showed the boys how he rode on a W-class tram when he was a schoolboy: hanging off the railing by one hand while standing on the running board, often simultaneously swinging a schoolbag overhead.

(A notice on one of the other out-of-commission trams in the yards warns of a $50 fine for such behaviour.)

It took the boys a bit of mastering, but was like muscle memory for the minister.

Mrs Larwill, who used to ride the same tram - number 722 - as a schoolgirl, long before she and Mr Larwill were a couple, also showed them how it was done.

The state government has conducted an audit of Victoria's 224 remaining W-class trams, most of which are held in storage at Newport Rail Yards.

Other older trams are also stored there, including a cable car dating from the late 1890s that is earmarked for restoration and a spot in a museum collection.

Twenty of those still stored at Newport are art trams, including those painted by Michael Leunig (1986), Merrin Eirth (1987), Bob and Lorraine Jenyns (1989), Lin Onus (1991), Jenny Watson (1992) and Aleks Danko (1993).

A reference group formed by Transport Minister Jacinta Allan in November will meet until April to decide what to do with the W-class trams.

They will call for expressions of interest from community groups, schools, arts organisations and even individuals who may be interested in buying or looking after one.

Some of the out-of-commission trams may return to the rails or be used for spare parts, as 12 of the W-class series continue to operate as part of the free City Circle tourist service and three for the Colonial Tramcar Restaurant.

VicTrack receives inquiries about W-class trams almost every day, a spokesman said, and had been in contact with some of the artists to let them know that the trams they painted are still in existence.