Original explosives expert for the gang, later replaced by Dynamit-Harry.
Harry takes over the explosives role previously associated with Rocky.
The plot describes Dynamit-Harry as contributing explosive expertise, while Rocky Blom is explicitly described as the original explosives expert later...
Their friendship survives their decision to leave active crime.
Ragnar Vanheden and Rocky Blom reject Sickan's offer while planning a respectable future, and the old friends remain connected.
Their connection comes from the gang's earlier lineup and Rocky's later absence from active operations.
Rocky Blom is identified as part of the gang's earlier criminal group, while the story states that Dynamit-Harry replaces Rocky.
Explore the full interactive character relationship map of The Jönsson Gang & Dynamite Harry
Related entry on Wikidata (Q114614463), public domain (CC0).