As Lagun are still in business & still make a version of this machine, it may be worthwhile asking them direct for a quote.
Most UK machine tool agents do rather "over egg" their spares prices, but I was (pleasantly) suprised at my last employment when I contacted Spanish manufacturer Zayer direct for a price on a set of 4 spiral bevel gears for a double angle universal head – a UK gearmaker had quoted several thousand to make a set to sample, where the OE parts were £500 and ex-stock. Carriage costs were not excessive either.
Contact details here : http://www.lagun.com.es/sat_en.html
Might come to nothing, but also costs nothing to ask.