Shared Line Index
There are a number of lines which recur in more than one of the Pucchā, and these are listed below. Note that lines that are repeated within one of the Pucchās are not listed here unless they occur in more than one of the Pucchā (in which case they are bracketed off).
Particularly noticeable in this list is that Ajita & Tissametteyya do not share lines with any other of the questioners; and that there is a strong connection between Puṇṇaka's & Nanda's Pucchās, and Mettagū's & Dhotaka's.
atthi pañhena āgamaṁ 1043b - Puṇṇaka; 1105d - Udaya; 1112d - Posala; 1118b - Mogharājā
Pucchāmi taṁ Bhagavā brūhi me taṁ 1043f (1045f, 1047e) - Puṇṇaka; 1049a - Mettagū 1061a - Dhotaka; 1079g (1081h) - Nanda
atāruṁ jātiñ-ca jarañ-ca mārisa 1045e - Puṇṇaka; 1079f - Nanda
atāri jātiñ-ca jarañ-ca mārisa 1047d - Puṇṇaka; 1081g - Nanda
Nātariṁsu jātijaran-ti brūmi 1046e - Puṇṇaka; 1080f - Nanda
atha ko carahi devamanussaloke 1047c - Puṇṇaka; 1081f - Nanda
anīgho nirāso, atāri so jātijaran-ti brūmī ti 1048cd - Puṇṇaka; 1061cd - Mettagū
Taṁ me muni sādhu viyākarohi 1052e - Mettagū 1075c - Upasīva
tathā hi te vidito esa Dhammo 1052f (1057d) - Mettagū 1075d - Upasīva; 1102d - Bhadrāvudha
Kittayissāmi te Dhammaṁ, diṭṭhe dhamme anītihaṁ 1053ab - Mettagū 1066ab - Dhotaka
yaṁ viditvā sato caraṁ, ~ tare loke visattikaṁ 1053cd (1054cd) - Mettagū 1066cd (1067cd) - Dhotaka; 1085cd - Hemaka (cf. 1087d - Hemaka)
Tañ-cāhaṁ abhinandāmi ~ mahesi Dhammam-uttamaṁ 1054ab - Mettagū 1067ab - Dhotaka
Yaṁ kiñci sampajānāsi, uddhaṁ adho tiriyañ-cāpi majjhe 1055ab - Mettagū 1068ab - Dhotaka 1103b (only) - Bhadrāvudha
Etābhinandāmi vaco mahesino, Sukittitaṁ Gotamanūpadhīkaṁ 1057ab Mettagū 1083ab - Nanda
akiñcanaṁ kāmabhave asattaṁ 1059b - Mettagū 1091d - Todeyya
Etad-aññāya ye satā, ~ diṭṭhadhammābhinibbutā 1087ab - Hemaka; 1095ab - Kappa
ācikkha Dhammaṁ yam-ahaṁ vijaññaṁ jātijarāya idha vippahānaṁ 1097de - Jatukaṇṇī 1120de (1122ef) - Piṅgiya;
pāraguṁ sabbadhammānaṁ, ~ atthi pañhena āgamaṁ 1105cd - Udaya; 1112cd - Posāla
Also note that 1084abcde = 1135abcde;
1006c - 1008d = 1124 - 1125;
988d = 1110d
& cf. 992b with 1105c
& 1112c.