Why i'm asking here's the reason.
If you see Saraighat's Present TB and Poorva's TB, there's a difference between these TB's.
Saraighat Express's present TB.
No star markings. No border visible.
Mostly...
more... Coach boards of Saraighat are seen.
HOWRAH-GUWAHATI-HOWRAH 12345 UP 12346 DN
हावड़ा-गुवाहाटी-हावड़ा 12345 UP 12346 DN
হাওড়া-গুয়াহাটি-হাওড়া 12345 UP 12346 DN
হাওৰা-গুৱাহাটী-হাওৰা 12345 UP 12346 DN
But in Poorva Express
Star markings visible. Borders visible.
Mostly Coach boards of Poorva are seen
12303/12381 UP HOWRAH-NEW DELHI POORVA EXPRESS 12304/12382 DN
12303 /12381 UP हावड़ा-नई दिल्ली पूर्वा एक्सप्रेस 12304 /12382 DN
12303/12381 UP হাওড়া-নিউ দিল্লী পূর্বা এক্সপ্রেস 12304 /12382 DN
See clearly.