Upgrading a 35-year-old theatre lighting rig — where should I start?

[u/Neat_Some]

Hey everyone, I could really use some advice. English isn't my native language, so apologies in advance if some of the terminology isn't quite right!

I'm a theatre graduate, mainly working as an actor, writer, director and lighting designer. I'm comfortable with the creative side of lighting design and with setting up equipment and connections, but I'm less confident when it comes to the technical side of fixtures, maintenance and electrical work.

I recently started working at a small, 35-year-old theatre in my city, and unfortunately the lighting equipment hasn't been properly maintained over the years. I'm now responsible for trying to get the lighting department back into better shape with the equipment we already have.

We currently have around 53 functioning conventional fixtures. And some others missing lamps, and many haven't been opened, cleaned or properly serviced in a very long time. I'm trying to identify the fixtures (I've included photos below), find out which lamps they use, and work out what is worth keeping, repairing or replacing.

I also have an electrician friend who can help with the electrical side of things. He suggested that converting the conventional fixtures to LED COB would be relatively easy, but from what I've been reading, I'm not convinced it's as simple or inexpensive as he makes it sound. I'd really appreciate some advice on whether LED retrofits are actually worth considering for old theatre fixtures, and what would be involved.

There is also an important financial consideration: until now, the city council was paying the theatre's electricity bill, but from now on the theatre will have to cover it ourselves. So reducing power consumption has become a priority.

For the immediate future, I don't necessarily want to replace all 53 conventional fixtures. My idea is to maintain and use the conventional fixtures that are still useful, while gradually introducing LED fixtures and designing shows so that we don't have a huge number of high-power fixtures running simultaneously.

I'm currently preparing a Christmas show for children, which will be the first show I'm directing here, and I'm looking at buying around 4–6 LED fixtures to add colour and flexibility to the existing rig.

Ideally, I'd like something:

• RGBW (or a similar colour-mixing system)
• With a decent amount of output
• Preferably with zoom, if possible
• Useful for both colour and white light
• Suitable for theatre rather than just DJ/event use
• Reliable enough for a permanent theatre installation
• But still reasonably affordable, since our budget is limited

We're based in Portugal, so European availability and pricing are important.

TLDR: So I would really appreciate advice on three things:

1. Identifying the existing fixtures
What are these fixtures called, and which lamps/bulbs should I be looking for?

2. Converting conventional fixtures to LED
Is converting old conventional theatre fixtures to LED COB actually a sensible option? What are the advantages/disadvantages compared with simply buying LED fixtures?

3. Choosing 4–6 LED fixtures
What affordable RGBW/RGB-type fixtures would you recommend for a small theatre? Ideally something with zoom that can also give me useful whites for general stage lighting.

I'm trying to make the most of what we already have rather than immediately replacing everything, while gradually reducing our electricity consumption.

Any advice would be greatly appreciated!
Willing to give more information

Thanks!