I also have a 1S1 and 1S2 but becasue they are rather special they have there own page.
I have the following plugins
D : Low frequency differential, 1mV-50V/cm, max 10000:1 CMRR (20KHz), max 50V common mode at 10mV and 500V at 100mV/cm (max 5V at the grid). DC to 2MHz
E : Differential audio amplifier 20KHz, adjustable filters, 50uV/cm, replaced bij the 1A7 and later 1A7A XRC audio jack input.
G and 53/54G : High frequency differential, 50mV-20V/cm, 100:1 CMRR at 20MHz, 50V common mode at 0,5V/cm and 200V at 5V/cm (2V at grid)
K : fast risetime DC coupled , 30MHz (fast in that time) and 12nS, 50mV/20V/cm
L : fast risetime AC coupled twin of the K, but higher gain (5mV/cm) and AC coupled.
O : very special, contains two operational tube amplifiers and switching gear for feedback restistors and capacitors. You can use it for very much experiments like measuring capacitance, BH curves, integrator, differentiator, pre-amp.
R : This is very rare, from the early transitor area used to analyse transistor schematics in common emitter and common base configuration, measures Tr, Tf, delay ect.
Z : Slideback differential amplifier and comperator, dynamic range +/- 100V (2000 cm or 0,005% resolution) 40000:1 CMRR and rather fast Tr/Tf. Used for instance for measurement on Zeners, output impedance transitors ect.
CA : 24 MHz dual channel allroubd plugin, 100% tubes. Very robust, upto 20V/cm
1A1 : 50MHz dual input with an extra output that let you feed the output of channel 1 in channel 2 to get 500uV/div
1A2 : Same as 1A1 but without the output
1A4 : the ultimate 4 channel input amplifier, 50MHz and on a 547 you can show 8 traces at the same time.
1A7A : For the uV hunter. 10uV/div and 50000:1 CMRR. adjustable filters, 500KHz BW