It's the first version of the meochrom. The mixing box is definitely different than the ones available for meochrom color-3's etc. It's more spherical, rather than a square looking box. I got a supplier to send me photos to compare and they are different. Not to say they wouldn't fit, but my guess is they wouldn't.
The reflector most definitely isn't built in. It fits in around the bulb, with a little tongue that slots into a little bracket on the bottom of the head chassis which is then secured with a long thumb screw. I doubt it's been modified. It all looks original to me, and certainly doesn't run off mains voltage. I use an external 12v transformer (which I need to check voltage for still - been moving house and my multimeter is at the bottom of a box somewhere.)
Interesting about the bulb socket. How does it affect the performance of the bulb do you know? I would have thought it just serves to mechanically hold the bulb in place. Any idea how I would know if it's causing problems (apart from bursting into flames, obviously)?
Sounds like your Meochrom is indeed much older than the ones I have used. Sorry for the unfounded optimism!
The usual thing with any low-voltage, high-current halogen socket is due to the temperature - there can more easily be a little bit of corrosion on the socket or bulb-contact. That puts the resistance up a fair bit so you get a much hotter socket and probably a lower current through the bulb. The halogen bulbs I have used in enlargers are different sizes, but have all had the standard two pin connector on the back. It looks like two little rods and these slide into a ceramic socket with springy contacts inside. The socket itself usually has heavy multi-core cable which is connected to the rest of the device with screw connectors, or some proprietary equivalent.
Over here we have the second-hand boards with plenty of meopta parts and enlargers. They were very popular in amateur use as they are well made and lined up accurately (in my experience, ymmv as they say). Maybe you can replace the whole enlarger for thirty euros or so? That would make much time or money expenditure, on repairs of the current one, less practical perhaps but it is an option.
If I see an older pattern of head for sale here I will let you know. They don't weigh much after all, so long as I didn't need to send the transformer!
Have a same problem with reflector on Meopta Meochrome color head.Can't have a good contrast because yellow metalic paint on reflector and it was like Y filter is always on.I have clean this yellow paint with fine sand paper until glass surface was mat.Glass surface must be mat because I have repaint reflector with aluminum heat resistance (600°C) paint.It's cheap paint here in Croatia (0,2 l about 4$).I have paint reflector twice inside and twice outside and next day put reflector in the oven (200°C) for about 20 min.Now you have nice silver heat absorbing color neutral reflector.Mixing chamber was repaint with white acrylic paint from hobby shop which is heat resistance (160-180°C).Halogen bulb surface is about 250°C.Because I have another color head (for parts) I have change Cyan filter with another Magenta and now there is 2 Magenta and 1 Yellow filter.With two Magenta on this color head it's possible to reach full contrast on any paper.
There is one more thing about Meopta Meochrome.Because of dust it's better that enlarger is grounded.This color head is not grounded..Trafo is grounded but head not.Cable from color head have plug with 3 contact but cable is with 2 wire.Female connector on the trafo have only 2 "live" contact,the third contact for ground doesn't exist inside female connector.Nearest ground contact that you can make is under big screw on trafo and the other end of the wire under big screw on the top of color head.Just my 0.02$.
Nice one. I'll have to try the paint thing. Im suspect my reflector is still affecting the colour of the light a little despite my bodgy foil fix. Contrast always seems a struggle but I've still not done the work to confirm that it's the enlarger and not development. Will have to try the earthing thing too.
Thanks for the comment!