C298 was also a bogie flat. C331 was an ex spoil wagon not mentioned so far.
From various issues of Irish Railfans' News
The first recorded use of spoil wagons on a ballast train was on 03.11.1967 during repairs to the line north of Ballymena after flooding. It was 10 spoil wagons plus coach 198 which was worked from Mageramorne to Ballymena by Jeep 51 and from there by MPD 44+36 with 51 banking. At Cullybackey the railcars were detached and No.51 then propelled the train on to Glarryford where the ballast was discharged
At Easter 1971 the wagons were located as follows
Magheramorne, 42; York Road, 3 (loaded); Antrim, 8 (loaded with limestone grit); Coleraine, 9 (all loaded bar one); and Lisburn, 8 (empty)
The wagon which went to Inchicore was M62 on October 2 1971. It was still on CIE at Easter 1972 but there is no further mention of its fate
The frames from two spoil wagons were used to construct two Goods Brake vans in Spring 1971, unfortunately their new numbers are not given