I have an early production (s/n 1547) .177 S70 with the Wischo branding.
It was purchased new in 1973 from Air Rifle Headquarters complete with the Air Rifle Monthly 48 page Special Handbook.
It likes 8.5 Japanese Jet pellets at 775 fps (newer spring & top hat)
One nice feature is the hardwood dowel through the grip area preventing the cracking that occurs on some Dianas and Feinwerkbaus.
Trigger adjustment is a tradeoff between travel and/or weight.
The trigger definitely benefits from the use of a trigger shoe.
The diecast pot metal sights and scope rail are a bit of a turnoff, but my Sept 1980 FWB124D III came with aluminum front and plastic rear sights.