Thanks a bunch guys!!
I´ve been doing some further research and the speakers in the cab are more recent than I initially thought. They were made early 2003 which suggests they were either some of the last ones made in England or the earliest (protos?) G12T-75s made in the far east still using many UK parts such as the paper cones.
In any case, I´m happy with the sound.
BTW I´ve got some further info about the UK - China transition, straight from Celestion´s mouth, published in 2003.
Q:Where are the current Celestion speakers manufactured (England or China)?
A: CELESTION COMMENTS ON COUNTRY OF ORIGIN FOR MANUFACTURING
Celestion has been manufacturing products in the UK since 1924. Nearly 10 years ago, Gold Peak, a Hong Kong based company, purchased Celestion and Kef in the UK. Gold Peak is a large manufacturer in the Far East and builds for JBL, Fender, QSC, Samson, and many others.
Their factories are first rate and in fact, do not offer the typical low cost manufacturing for which China is known.
In the last few years, Celestion determined they would need to relocate from their site in Ipswich as the factory was very old, run down, and inefficient. Looking in the UK, Europe, and the Far East, it was evident that using the existing company facilities in China was the best alternative to keep up with record demand levels and continue to match performance. Earlier in 2003, Celestion began moving most production to China. The products still manufactured in the UK, in a brand new facility, include the AlNiCo Blue & Gold, G12M & G12H Heritage, and all Neo Products, including Century/Century Vintage/ BL Neo. Celestion doesn’t manufacture piece parts in this factory, so the paper cone assemblies could very well still be sourced from the original supplier in the UK. That is simply a supply chain decision. The early boxes coming out of China were not always marked with the county of origin, current production boxes should be clearly marked now as to country of origin.
In November 2003, Celestion flew the editors from most of the major Guitar and Music Trade publications to the UK to outline their manufacturing strategy and give them a preview of the new Celestion speakers. We should start seeing the articles in print by January 2004.
Celestion’s experience with the actual performance of the Far East product has been excellent. In fact, they’ve reported a more consistent result driver to driver across production runs. Their “blind tests”, with all of their major OEM customers have been successful, and Celestion’s business continues to grow at record levels. It's important to consider that Celestion did NOT go to an outside contract manufacturing company for production (like some other speaker manufacturers) – they used an existing company owned facility in China that had been making the Truvox range of lower cost guitar speakers for years.