Stage management would have 'marked up' the floor of the rehearsal room. Some theatres have their own rehearsal space within the main theatre building. At Liverpool Playhouse, for example, which could also be used for small-scale, studio performances, but generally most 'reps' had to make do with either rehearsing on the actual stage, that is, if the current show had space within it's acting area, but usually rehearsals would be held somewhere in the town such as a church hall or other convenient space where the floor-plan of the set could be marked out using coloured tape or even chalk. Doors, stairs and different levels of the set would be marked and then furniture placed in the position it would be on the set. This would most likely be stand-in furniture as most likely not all the furniture for the actual production would be ready for use in the rehearsal studio.
Then the 'blocking' of the play would begin. If actors were not required for a particular scene they wouldn't be 'called' until later, but whoever was responsible for running the rehearsals, generally the person doing 'The Book' would have to keep a tally of rehearsal 'calls' usually given by the director at the end of a day's rehearsal and then the D.S.M. would have to make up a call sheet giving calls for the actors for the next day or for the days ahead. The whole play would most likely be broken up into scenes or acts and the actors required for those scenes or sequences of the play would only then be needed for their scenes. You would most likely have to telephone those actors who were elsewhere to give them their calls.
'Blocking' is the initial direction given by the play's director, the moves the actors make around the stage. During this process the person on the book has to mark all these moves as precisely in the prompt copy so that, if needs be, the director or actors can be remind where a particular move is. At the same time, another member of stage management is plotting all props, what they are and where they are set on or off stage, if they come on from a particular entrance which is important so that at the beginning of the play stage management know where to set them. It is at this point, when there is a list of props, that stage management begin to find props. Some theatres have a properties department, a store-room which contains a fair amount of items which can be used in any particular play, be it a set of candle sticks, teapots, cups and saucers or smaller items of furniture, but if it's something more complicated, such as a stuffed bear (which is what we were supposed to find for a play I did in Liverpool.) or a samovar (which I had to find when working on a play in Cheltenham. Yes, I did manage to find one, in an antiques centre.) then you would be expected to walk the streets of the town in which the theatre was in and literally 'beg, borrow or steal' to get items to use on-stage. We seemed to have a regular selection of shops, mostly antique shops, who would be willing to lend items of furniture, and then we got on good terms with the display departments of certain department stores who used to provide all manner of items. On a production of 'Salad Days' at Cheltenham Everyman we needed to find a couple of hairdryers, the sort you would find in a hairdressing salon. I found out that Cavendish House, the large department store opposite the theatre, was modernising their hairdressing department and found that they were throwing out their old driers, so we managed to borrow them for the show. Perfect, and they even came on castors which made it easy during a scene change. They could then be simply wheeled on and off stage during the scene change.
Before the actual props are available (and some can be hired from a range of prop hire companies) we also had to provide 'stand-in' props, so the actors had something to handle during rehearsals. It's a bit difficult, for example, if a scene is set during a meal and the actors don't have plates and cutlery, or drinking in a bar and don't have something to drink out of. Once they have got their lines learnt and aren't carrying their scripts then they will want to have something to work with as regards props. The same goes with furniture. They need chairs to sit on and if there is a sofa, a group of chairs pushed together to stand in for a sofa which may not have been sourced.