It'd be almost a shame to put 2020 black Tektro levers onto a 1970s/80s bike that's almost pristine original as it rolled out of the shop, down to the reflectors and bar tape. Though someone clearly replaced the brake cables, which suggests that it was ridden, and taken care of.
My first 700c bike in the early 90s, with Weinmann brakes, had the suicide levers and rubber brake hoods over them. It was vanishingly rare to see that.
I'd say replace the bar tape with something with a bit of cushion, and if you do ever find yourself riding with your hands on the hoods, just get used to wearing gloves/mitts. You probably wear something on your hands most of the year round in midlands English weather.
Actually, these Dia-Compes look like they might be the ticket; they have punch-out holes to allow for the "extenders." Just wish they came in white.
https://www.ebay.co.uk/itm/Dia-Compe...EAAOSwugJeefMM
13 squid plus P&P.