In this post https://abn397.wordpress.com/2021/09/18/delhi-to-madras-by-metre-gauge-in-1976/
we had explored an all-MG route between Delhi and Madras which existed in 1976, as well as the extremities of metre gauge at Kot Kapura and Tiruchendur at that time,
In 1976, the extremities of metre gauge were Varvala (near Okha) in the west and Lekhapani (near Ledo) in the east. These were also the extremities of IR as broad gauge had not spread to these areas yet.
Here, we travel from Okha (the western-most terminus) to Lekhapani.

Names are as they were in 1976. There do not seem to have been any instances of inflated distances on this route.
WEST TO EAST BY METRE GAUGE IN 1976 | |||
Km | |||
0 | Okha | ||
29 | Dwarka | ||
141 | Kanalus | ||
166 | Jamnagar | ||
247 | Rajkot | ||
289 | Wankaner | ||
365 | Surendranagar | ||
428 | Viramgam | ||
493 | Mahesana | ||
563 | Palanpur | ||
616 | Abu Road | ||
781 | Marwar Jn | ||
869 | Beawar | ||
921 | Ajmer | ||
1001 | Phulera | ||
1056 | Jaipur | ||
1147 | Bandikui | ||
1244 | Bharatpur | ||
1272 | Achhnera | End of WR | |
1307 | Mathura | ||
1358 | Hathras Road | ||
1412 | Kasganj | ||
1520 | Farukhabad | ||
1660 | Kanpur Central | ||
1731 | Lucknow | ||
1763 | Barabanki | ||
1791 | Burhwal | ||
1852 | Gonda | ||
2006 | Gorakhpur | ||
2076 | Bhatni | ||
2125 | Siwan | ||
2185 | Chhapra Jn | ||
2240 | Sonpur | ||
2245 | Hajipur | ||
2316 | Bachwara | ||
2332 | Barauni | ||
2388 | Khagaria | ||
2511 | Katihar | End of NER | |
2551 | Barsoi | ||
2606 | Kishanganj | ||
2713 | Siliguri Jn | ||
2761 | New Mal |
2876 | Alipurduar Jn | |
2948 | Fakiragram | |
2985 | New Bongaigaon | |
3095 | Rangiya | |
3158 | Gauhati | |
3250 | Chaparmukh | |
3339 | Lumding | |
3408 | Dimapur | |
3516 | Mariani | |
3570 | Simaluguri | |
3671 | Tinsukia | |
3725 | Ledo | |
3734 | Lekhapani | NFR |

As you can see, this route passes through only three of the existing zones at that time.
It passed through the states of GJ, RJ, UP, BR, WB, AS and NL.
While the Sonpur-Muzaffarpur-Samastipur-Barauni section was already broad gauge, most of the long-distance trains continued to run on MG as the BG lines were too limited in these areas.
The Ledo-Lekhapani section had very limited services of one pair of trains per day. It was opened in the late 1950s after conversion of a privately-owned 2’0″ NG line. Later, it was not found worthwhile to convert to BG so Ledo remains the eastern-most passenger station. The BG line continues a little further east to Tirap Siding where coal is loaded on goods trains.
A possible set of trains for this route (from 1976) are:
Okha-Mahesana Janata Express to Mahesana
Various express trains to Jaipur or Bandikui.
Various express/passenger trains to Achhnera or Agra Fort.
Vaishali Express to Siliguri. (Yes, at that time it started from Agra Fort).
Various express trains to Tinsukia (Assam Mail was direct, otherwise change at NBQ).
Various passenger trains to Ledo.
One passenger train to Lekhapani.
Today, we have through BG trains from Gujarat to Assam.