My mothers family lived in Workington and I spent all my holidays there until 1966, the year the Workington-Keswick section closed.
The reason this section closed was Beechings ignorance of what was later to be called contributory revenue and the fact that station surveys were done in February deliberately.
Revenue from fare boxes on the line was perhaps low between September and Easter but in the Summer additional local trains were run on Sundays from Whitehaven to Keswick. These were loco-hauled with up to eight coaches and full every Sunday by the time they left Workington.
On Summer Saturdays there were timetabled and excursion trains from Newcastle, Manchester and Birmingham between Penrith and Keswick and London right through to Workington as the 'Lakes Express'. At Easter during Keswick Convention there could be up to five through trains from London. It was not uncommon for Royal Scots and Jubilees to work right through to Keswick on all these trains and Keswick could be quite congested in the carriage sidings and turntable area on the west side of the station. I never saw a Britannia or Stanier Pacific on these trains but there were rumours of a Clan Pacific working a train.
Axle loading restrictions onwards to Cockermouth and Workington prevented these trains from running through to Workington ECS for stabling there if there wasn't a quick turnround for a return service.
When Workington-Keswick closed in 1966 and was lifted, the carriage sidings and turntable were not available. By 1968, there wasn't even a run round facility and any excursion had to be top and tailed. 1968 was the last year I saw a Convention special as they had dwindled to only one and of course the Lakes Express no longer ran after 1965 as the Workington line closed before the 1966 Summer timetable.
The point is that for all additional through trains and connecting local trains at Penrith, visitors to Keswick bought their return tickets somewhere else on the network that didn't show in the Keswick station farebox that Beeching looked at to assess his cuts. A similar thing happened at seaside resorts that have lost their rail service also.
Even before Penrith-Keswick closed in 1972, those that travelled to Keswick previously by through trains had already transferred to car and road coach as the facility had been withdrawn. No only did Keswick station lose but the overall revenue to BR reduced because of modal shift caused by Beeching in the first place.
The M6 motorway and improved A595, now A66, had also arrived in 1967/68. Ironically, in 1974, introduction of the Electric Scots knocked an hour off London-Penrith journey times with through trains every two hours. The best service Penrith had ever had.
I think a reinstated, modern signalled, electrified railway with good quality rolling stock and reduced journey times to Penrith/Carlisle capable of taking through trains/portions would be a winner. Off line deviations around parts that are now under the A66 is no problem even along Bassenthwaite Lake as Victorian trackbeds are taken apart nowadays and are virtually new build anyway as shown with Borders line reinstatement for approximately £8m/mile.
For the doubters, a facility can't be used unless it is there and Benefit/Cost analysis has been shown to be wrong in nearly every reinstatement case. Build it and they will come.