I'd like to change the 1960's sliding doors between our lounge and
dining room to a pair of double doors.

In order to match the other doors in the house I was thinking of buying
two ordinary doors, routing a rebate on them and using a rebated
mortice latch. However the door are 'engineered' panel doors and I
would be limited to a rebate of about 7 or 8 mm. Is this a sufficient
overlap (it doesn't seem much after allowing for a gap of perhaps a
couple of mm), or do I really need more? Does a small overlap like this
cause problems with the rebate latch, or can I just recess the latch
and striker to match the rebate depth.

Roger