I think the full list is something like below. Taken from
http://www.heritagerailways.com/Visits_Map.php
Aberystwyth Cliff Railway
Alford Valley Railway
AmberleyMuseum
Amerton Farm Railway
Astley Green Colliery Museum
Avon Valley Railway
Ayrshire Railway Preservation Group
Babbacombe Cliff Railway
Bala Lake Railway
Barrow Hill Railway Centre
Battlefield Line
Beamish
Bishop's Castle Railway Society
Bluebell Railway
Bo'ness & Kinneil Railway
Bodmin & Wenford Railway
Bowes Railway
Brecon Mountain Railway
Bredgar & Wormshill Light Railway
Bressingham Steam & Gardens
Bridgnorth Cliff Railway
Buckingham Railway Centre
Bure Valley Railway
Caledonian Railway
Cambrian Heritage Railways
Cavan & Leitrim Railway
Chasewater Railway
Chatham Historic Dockyard
Chinnor & Princess Risborough Railway
Cholsey & Wallingford Railway
Churnet Valley Railway
Cleethorpes Coast Light Railway
Colne Valley Railway
Colonel Stephens Railway Museum
Corris Railway
County Donegal Railway
Crewe Heritage Centre
Darlington Railway Centre & Museum
Darlington Railway Preservation Society
Dartmoor Railway
Dartmouth Steam & Riverboat Company
Dean Forest Railway
Derbyshire Dales Narrow Gauge Light Railway
Derwent Valley Railway
Devon Railway Centre
Didcot Railway Centre
Dolgarrog Railway Society
Downpatrick & County Down Railway
East Anglia Transport Museum
East Anglian Railway Museum
East Kent Railway
East Lancashire Railway
East Somerset Railway
Ecclesbourne Valley Railway
Eden Valley Railway
Elsecar Heritage Railway
Embsay & Bolton Abbey Railway
Epping & Ongar Railway
Exbury Gardens & Steam Railway
Fairbourne & Barmouth Railway
Ffestinog and Welsh Highland Railways
Fintown Railway
Folkestone Leas Lift
Foxfield Railway
Giants Causeway & Bushmills Railway
Gloucestershire Warwickshire Railway
Golden Valley Light Railway
Great Central Railway
Great Central Railway, Nottingham
Great Laxey Mine Railway
Great Orme Tramway
Groudle Glen Railway
Gwili Railway
Headhunters Barbershop & Railway Museum
Helston Railway
Hollycombe Steam Collection
Irish Steam Preservation Society
Isle of Man Steam Railway
Isle of Wight Steam Railway
Keighley & Worth Valley Railway
Keith & Dufftown Railway
Kent & East Sussex Railway
Kidderminster Railway Museum
Kirkby Stephen East Heritage Centre
Kirklees Light Railway
Lakeside & Haverthwaite Railway
Lappa Valley Railway
Lartigue Monorail and Museum
Launceston Steam Railway
Lavender Line
Leadhills & Wanlockhead Railway
Leighton Buzzard Railway
Lincolnshire Coast Light Railway
Lincolnshire Wolds Railway
Llanberis Lake Railway
Llangollen Railway
Locomotion
London Transport Museum
Lynton & Barnstaple Railway
Lynton & Lynmouth Cliff Railway
Mangapps Railway Museum
Merseyside Tramway Preservation Society
Mid Hants Railway
Mid-Norfolk Railway
Mid-Suffolk Light Railway
Middleton Railway
Midland Railway Centre
Moseley Railway Trust
National Railway Museum
National Tramway Museum
Nene Valley Railway
North Bay Railway
North Ings Farm Museum
North Norfolk Railway
North Tyneside Railway
North Yorkshire Moors Railway
Northampton & Lamport Railway
Northamptonshire Ironstone Railway Trust
Old Kiln Light Railway
Peak Rail
Perrygrove Railway
Plym Valley Railway
Pontypool & Blaenavon Railway
Princess Royal Locomotive Trust
Railway Preservation Society of Ireland
Railworld
Ravenglass & Eskdale Railway
Rhyl Miniature Railway
Ribble Steam Railway
Romney, Hythe & Dymchurch Railway
Royal Deeside Railway
Rudyard Lake Railway
Ruislip Lido Railway
Rushden Transport Museum
Rutland Railway Museum
Seaton Tramway
Severn Valley Railway
Shipley Glen Tramway
Sittingbourne & Kemsley Light Railway
Snowdon Mountain Railway
Somerset & Dorset Heritage Trust
Somerset & Dorset Railway Trust
South Devon Railway
South Tynedale Railway
Spa Valley Railway
St Albans South Signal Box
STEAM: Museum of the Great Western Railway
Steeple Grange Light Railway
Stephenson Railway Museum
Strathspey Railway
Swanage Railway
Swindon & Cricklade Railway
Talyllyn Railway
Tanfield Railway
Teifi Valley Railway
Telford Steam Railway
The Wells & Walsingham Light Railway
Timothy Hackworth Railway Museum
Tralee & Dingle Light Railway
Ulster Folk & Transport Museum
Vale of Rheidol Railway
Vintage Carriages Trust
Volks Electric Railway
Waterford & Suir Valley Railway Company
Waverley Route Heritage Association
Weardale Railway
Welsh Highland Heritage Railway
Welshpool & Llanfair Railway
Wensleydale Railway
West Clare Railway
West Lancashire Light Railway
West Somerset Railway
Whitwell & Reepham Railway
Yeovil Railway Centre
