35W 1x15 bass combo — the Supro that became a guitar-amp cult favourite.
Marks that can be entered for this maker: Serial number (plate), Transformer code, Chassis stamp.
Nothing predates 1960; components only push the date later.
Sold-price aggregates are not collected yet, so the archive gives no figure — condition, originality of the transformers and a documented recap move this model more than any list price.
Evidence: Blue Book of Guitar Values — supro