Other people are doing the same good work.
We were first inspired to start going to sessions by the Spare Parts workshops at Chippenham. They used tunes from the Lewes Favourite , which is online.
And at Whitby George Garside usually runs a 'Slow and Steady session' and May Cheadle an even slower 'Not quite ready for a session'. These don't give out sheet music - though a lot of the tunes played are from the David Oliver collections
(and no-one says you can't take a peep at your books). Both of those are run with the rules that anyone can suggest a tune, if enough people want to play it it is played, led by the one who suggested it unless they want the session leader to, and NO RUSHING.
And google just found a Slow & Steady session at Towersey, run by David Oliver.

Worth learning some tunes from either of those collections as they are commonly played in sessions (though there is a bit of a North/South divide in popularity)