What a co-incidence.
I found the same Celica wheel on ebay here in the UK, with airbag but
no clock spring. I left it with a garage to fit it when the truck was in for a gearbox flush. The garage told me the stock Surf / 4Runner clock spring
plugs were incompatible with the airbag on the wheel.
I saw Charlie's (TorqueOfTheD) comment that his Lexus clock spring swapped straight over, so I found a Celica one on aliexpress and that showed up today. But then I also saw what the stock Surf / 4Runner clock spring looks like and they are a different shape in terms of screw fitment.
I was thinking I was screwed and to just offload the wheel, when I wondered if just the plugs could be swapped. Et voila, here's your post. I'll take my Celica clock spring down to them and see if they will just splice the plug to the stock clock spring as you did.
For what it's worth, I believe physically most of the same-era wheels will swap, but it's the clock springs (and their plugs) that dictate whether you can retain the airbag.
Stock clock spring part for Surf/4Runner 3rd gen is 84306-12070 or 84306-35011.
If you search for those on
AliExpress.com - Online Shopping for Electronics, Fashion, Home & Garden, Toys & Sports, Automobiles from China. you can get an idea of the shape. 84306-35011 will fit (according to them):
This part fits for following models:
Euro-market:
1997-1997 PASEO EL54
1997-1999 CAMRY (JPP) MCV20,SXV20
1997-1999 CAMRY MCV20,SXV20
1997-1998 PICNIC CXM10,SXM10
1997-1997 RAV4 SXA1#
1997-1997 4RUNNER RZN18#,VZN18#
1997-1998 LAND CRUISER 90 KZJ9#,VZJ9#
General market:
1997-1997 PASEO EL54
1997-1998 CROWN COMFORT LXS10
1997-1998 TOWNACE/LITEACE SR40
1997-1997 RAV4 SXA1#
1997-1997 4RUNNER RZN185,VZN185
1997-1998 LAND CRUISER 90 RZJ95,VZJ9#
North American market:
1997-1999 CAMRY (JPP) MCV20,SXV20
1997-1997 RAV4 SXA1#
1997-1997 4RUNNER RZN18#,VZN18#
Japanese market:
1997-1997 CORSA/TERCEL EL5#,NL50
1997-1997 COROLLA 2 EL5#,NL50
1997-1998 CYNOS EL5#
1997- CAMRY/VISTA SV4#,CV4#
1997-1998 MARK 2 GX100,JX10#,LX100
1997-1998 CHASER GX100,JZX10#,LX100,SX100
1997-2000 CROWN COMFORT/SED GXS10,LXS11,SXS11,YXS1#
1997-1998 IPSUM CXM10,SXM1#
1997-1998 LITE/TOWNACE NOAH,V CR4#,CR5#,KR4#,SR40,SR50
1997-1997 RAV4 SXA1#
1997-1997 HILUX SURF KZN185,RZN185,VZN185
1997-1998 LAND CRUISER PRADO KZJ9#,RZJ9#,VZJ9#
Those should be a straight swap and retain your clock spring as the airbag plugs should match.
The Celica clock spring is 84306-52010 if you just want to order this and then use the new Celica plug on your stock clock spring to allow you the Celica wheel above (1999 MY).
Hope this helps!