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postage
1970, Jul 23 1970 issue unwmk p. 14
| X | 160 | org | Heinemann | — | — |
1975, May 15 1975 issue - technology (1975)
| X | 160 | grn | Large blast furnace with hot blast stove system |
1 to 2 of 2
| X | 160 | org | Heinemann | — | — |
| X | 160 | grn | Large blast furnace with hot blast stove system |