oh dear - I think you have us all stumped
Not many places with no stairs (I believe Grants is nice but presume stairs (not been myself) and not many places with a jukebox these days.
Is money no object? I hired a jukebox for my hubby's birthday but it cost as much as, if not a little more, than a DJ.
Accrington golf club would look empty with only a few guests. GreenHaworth golf club has steps up to it (but maybe they've made disabled access since I went last - many years ago)
Ooooo - I know....Peel Park Pub. Lovely catering - I went to a funeral there about 6 months ago (not too expensive I believe) normal pub prices, quite central to accy (for people getting transport/taxis) disabled access round back for elderly/disabled and a lovely recently renovated room, and 70 would probably just about fill it!
If I was having a christening - I think that's where I would have it!
Job done me thinks ;-)