Is the Foundry BR-FGS624P switch stackable by adding the 10GbE ports, or is it never stackable?

Question

I'm looking at buying a Foundary BR-FGS624P 24 port switch which will suit our purposes now, but thinking into the future I might like to stack the switch when we add a few more servers to our rack.

The FGS624P-STX model supports stacking, but I don't see many on sale at eBay, so I'm wondering if the non-stacking model can be upgraded to support stacking simply by buying the 10GiE ports (2 maximum).

Specifically I'm looking at this model:

http://www.ebay.com/itm/Foundry-BR-FGS624P-24-Port-E-FE-GE-4xSFP-Gigabit-Ethernet-Switch-RPS-FGS-600W-/390490417051?pt=US_Network_Switches&hash=item5aeb0ae79b

The show mod readout seems to suggest to me that it is stackable when/if I buy the 10GiE ports for it.

BR-FGS624P Router#show mod
    Module                                           Status Ports Starting MAC
S1: FGS-24G 24-port Management Module                OK     24    0012.f27d.6a00
S2:
S3:
S4:
BR-FGS624P Router#show ver
  SW: Version 04.3.02bT7e1 Copyright (c) 1996-2008 Foundry Networks, Inc.
      Compiled on Sep 21 2009 at 16:04:58 labeled as FGL04302b
      (3268159 bytes) from Primary FGL04302b.bin
      BootROM: Version 05.0.00T7e5 (FEv2)
  HW: Stackable FGS624P
==========================================================================
STACKID 0: SL 1: FGS-24G 24-port Management Module
      Serial  #: CH34061240
      P-ASIC  0: type D804, rev 01
==========================================================================
  400 MHz Power PC processor 8245 (version 129/1014) 66 MHz bus
  512 KB boot flash memory
 8192 KB code flash memory
  128 MB DRAM
The system uptime is 1 minutes 24 seconds
The system : started=warm start   reloaded=by "reload"

BR-FGS624P Router#show flash
Compressed Pri Code size = 3268159, Version 04.3.02bT7e1 (FGL04302b.bin)
Compressed Sec Code size = 1919636, Version 02.6.00T7e1 (/tftp/fgs02600.bin)
Compressed BootROM Code size = 416213, Version 05.0.00T7e5
Code Flash Free Space = 1048576
BR-FGS624P Router#show chassis
Power supply 1 (NA - AC - Regular) present, status ok
Power supply 2 not present

Fan 1 ok
Fan 2 ok
Exhaust Side Temperature Readings:
        Current temperature : 28.5 deg-C
        Warning level.......: 85.0 deg-C
        Shutdown level......: 90.0 deg-C
Intake Side Temperature Readings:
        Current temperature : 23.0 deg-C
Boot Prom MAC: 0012.f27d.6a00
Management MAC: 0012.f27d.6a00
BR-FGS624P Router#