I've been asked a few times when this was introduced. Jan 1988 was first advertised to shooters.
A complete conversion for your HW77.New parts-
Compression tube, piston & piston head, guide tubes plus hand finishing of body tube, cocking lever and trigger block.
The Lazaglide features -
Leak tested nickel plated compression tube and high tech alloy piston both with synthetic bearings to ensure no metal to metal contact.
A complete conversion on your 77 carried out at the venom workshop was £98.00 in Jan 1988. By April of that year the system was available for the HW80, 85, Diana 52 and the Webley Eclipse.
Mach 1.5