Well, that's easy then, innit?
I knew I shouldn't have but I did anyway - story of my life! - and used my Progress this morning. Can't see detail without my glasses but managed to set the thing to '3'. It felt a tad aggressive but I put that down to the razor rash from heavy handed straight shaving on Monday.
Later, with glasses on, I realised I'd shaved with the Progress effectively set at '5.5' because the dial is not calibrated correctly - the first position is 2.5 stops to the left of the mark. I'd forgotten that!
Then I received an email from Lee saying he had Mergresses in stock. Turned out he did not have long handled versions in stock so I bought an XL - short handled Progress with a long Mergress knob, thinking it would do. What I'd really like is a long handled Progress with a long Mergress knob, so ...
The Progress I have needs calibrating correctly and if I could get that one apart then I could fit the Mergress knob to it when it arrives and the Progress knob to the short handled razor ex-Lee. That would give me the Mergress I want and a short handled Progress to sell or PIF.
Getting them apart is somewhat obvious with the razor in hand so my Progress is now correctly calibrated and the aggressiveness taken out of it, awaiting delivery of a Mergress razor.
Happy bunny! Bet there aren't many Mergresses like mine is going to be - a long handled XL.