Swap 525i and 520i for 525i... Would you do it?

The other day, I passed a local "classic car" used lot. Amid the usual old Austins and MGs, I found a '92 525i with 121,000 miles. It's Brilliantrot with black interior, with a 5spd, M50 non-Vanos, heated manual cloth seats with arm rests, air conditioning, OBC, cruise control, the original radio/cassette, M-Tech steering wheel, and sunroof. The asking price is £1250, as I recall, but £900 or so is probably what it's worth.

On the plus side, the interior is pristine but for a missing rear ashtray, the engine starts and runs well with no unpleasant noises, clutch and tranny seem good, the bodywork is generally straight and rust-free, the paint looks like it'll polish up real sweet, and it even comes with the OEM first-aid kit under the passenger's seat.

Here are the minor minuses:

• Fuel door hinge is broken.
• Minor rust under fuel door, with some of those can't-aim-the-filler-nozzle-worth-**** scratches above it.
• Minor scratches/dents on one C pillar -- touch-up paint will fix the scratches.
• One of those ornamental nut caps on the engine cover is missing, as are some of the plastic screws that secure the covers behind the headlights. (Well, I did say these were minor, didn't I?)
• Electrician's tape is wrapped around the idle stop on the throttle body, apparently to boost the idle speed. Some of the air lines are cracked, so this is probably a bodge to get around a poor idle caused by air leaks and/or a flaky ICV.
• Minor paint bubbling on one door corner.
• The left front foglight mounting is screwed, or the foglight itself is a non-E34 item; it's recessed oddly into the air dam. I didn't look too closely.
• The HVAC microfilter is undoubtably plugged; air flow is poor.
• The check warning system throws a brake wear warning, but the pads are obviously almost new. Some goof probably forgot or didn't bother to install new wear sensors.
• A rear ashtray is missing.
• A couple of tools are missing from the set (I forget which), but the warning triangle is there.
• Aftermarket wheels (not bad, but not great) are shod in well-worn tires, but new tires (less than 1000 miles) and four BMW (chassis unknown!) wheels are included. I haven't seen these yet, so until I do, I'm counting it as a minor minus rather than a plus.
• The valve cover gasket is leaky.
• The washer tank is empty. While it might simply have been run dry, I'm inclined to suspect the o-ring and/or the pump itself are leaky. This is a common problem.

Here are the bigger minuses:

• Rear exhaust box is shot and must be replaced.
• The air conditioning does not work; the pushbutton light doesn't come on, and one small black relay is missing from the fusebox. I haven't yet tracked down which relay it is, but I (obviously) suspect it's A/C related.
• The aux fan is seized tighter than a gnat's chuff. The associated fuse is blown, not surprisingly.
• Coolant has apparently been disappearing, as evidenced by a lowish water level in the rad, not much antifreeze in the mix, and an ominously empty bottle of blue coolant in the boot tray. A rad hose was damp on the underside, but it was a dewy night so it could be condensation. Or... Possibly the heater matrix due to rag stuffed along the junction between the console and the carpet, but maybe this is to dampen a rattle (he wrote, hopefully...)? No evidence of head gasket problems.

I do all my own mechanical work, so shop labour isn't a factor.

I haven't driven it yet. When I went to try it, the rusty fuel return pipe popped and drizzled fuel on the exhaust system. Show and Tell was terminated abruptly before any fireworks started. The seller is fixing it as I write this, and I'll give it a trial run on Monday.

Here's the thing: I suggested to the seller that we *might* do a straight swap: My 1990 525iA plus my '87 E28 520i for his '92 525i. The seller likes the idea, but I'm not yet convinced.

Keep in mind that my 525i is considerably worse, cosmetically, than the '92. Many more dents and scratches, a ripped driver's seat, and a hole in the driver's armrest from somebody's amazingly sharp elbow. Also, it's further down the options food-chain -- no OBC, cruise, A/C, or heated seats & arm rests -- and, of course, it's got the M20 engine and a slushbox instead of the M50 and 5spd manual. It's also higher mileage. If I sold it on eBay, I'd probably get about £650 for mine. Maybe less because the MoT certificate (gov't mandated inspection) has just run out.

My 520i is running, cosmetically good except for a dented rear bumper, but it needs new brake pads and discs and it runs on TRX wheels. It's been off the road for over a year. If I sold it on eBay, I'd be lucky to get £200 for it.

So, here's my question: Given the above, would you do the swap?

Most of the problems with the 92 are pretty small fixes, nothing too serious. If you feel confident about it and are ready to do a bit of an upgrade, as well as have a pretty badass M50, do it up!